GD(STI)-11
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
2. Diagnostic Trouble Code (DTC) Detecting Criteria
A: DTC B1570 ANTENNA
1. OUTLINE OF DIAGNOSIS
2. ENABLE CONDITIONS
When starting the engine.
3. GENERAL DRIVING CYCLE
Perform the diagnosis only after starting the engine.
4. DIAGNOSTIC METHOD
Judge as NG when the conditions for the outline of the diagnosis of the top are established.
DTC Item OUTLINE OF DIAGNOSIS
B1570 Antenna Faulty antenna
B1571 Reference Code Incompatibility Reference code incompatibility between body integrated unit and
ECM
B1572 IMM Circuit Failure (Except Antenna Circuit) Communication failure between body integrated unit and ECM
B1574 Key Communication Failure
The body integrated unit to confirm the key (transponder) ID code has
malfunction, of the transponder is faulty.
B1575 Incorrect Immobilizer Key
Incorrect immobilizer key (Use of unregistered key in body integrated
unit)
B1576 EGI Control Module EEPROM ECM malfunctioning
B1577 IMM Control Module EEPROM Body integrated unit malfunctioning
B1578 Meter Failure
Reference code incompatibility between combination meter and body
integrated unit
15WRX_STI_US_EN.book 11 ペー   
GD(STI)-12
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
B: DTC B1571 REFERENCE CODE INCOMPATIBILITY
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC B1570. <Ref. to GD(STI)-11, DTC B1570 ANTENNA, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
C: DTC B1572 IMM CIRCUIT FAILURE (EXCEPT ANTENNA CIRCUIT)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC B1570. <Ref. to GD(STI)-11, DTC B1570 ANTENNA, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
D: DTC B1574 KEY COMMUNICATION FAILURE
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC B1570. <Ref. to GD(STI)-11, DTC B1570 ANTENNA, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
E: DTC B1575 INCORRECT IMMOBILIZER KEY
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC B1570. <Ref. to GD(STI)-11, DTC B1570 ANTENNA, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
F: DTC B1576 EGI CONTROL MODULE EEPROM
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC B1570. <Ref. to GD(STI)-11, DTC B1570 ANTENNA, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
G: DTC B1577 IMM CONTROL MODULE EEPROM
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC B1570. <Ref. to GD(STI)-11, DTC B1570 ANTENNA, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
H: DTC B1578 METER FAILURE
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC B1570. <Ref. to GD(STI)-11, DTC B1570 ANTENNA, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
15WRX_STI_US_EN.book 12 ペー   
GD(STI)-13
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
I: DTC P000A A CAMSHAFT POSITION SLOW RESPONSE (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the AVCS system malfunction.
Judge NG when the amount of AVCS actual timing advance does not approach to the amount of AVCS target
timing advance.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously while AVCS is operating.
5. DIAGNOSTIC METHOD
When the differences of target timing advance amount and actual timing advance amount is calculated dur-
ing AVCS control, and the difference per predetermined time is the specified value or larger.
Judge as NG when the following conditions are established within the predetermined time.
Time Needed for Diagnosis: 25000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) AVCS timing controller (3) Engine control module (ECM) (5) Oil pressure
(2) Vane (4) Oil flow control solenoid valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
AVCS control Operation
Target timing advance change amount (per 64 ms) < 10 °CA
Judgment Value
Malfunction Criteria Threshold Value
Σ(Target position – Actual position) > 4000 °CA (Bank 1)
> 4000 °CA (Bank 2)
or
Σ(Target position – Actual position) < –4000 °CA (Bank 1)
< –4000 °CA (Bank 2)
EN-01852
(3)
(4)
(1)
(5)
(2)
15WRX_STI_US_EN.book 13 ペー   
GD(STI)-14
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
J: DTC P000B B CAMSHAFT POSITION SLOW RESPONSE (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the exhaust AVCS system malfunction.
Judge NG when the amount of exhaust AVCS actual timing advance does not approach the amount of ex-
haust AVCS target timing advance.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously while exhaust AVCS is operating.
5. DIAGNOSTIC METHOD
When the differences of target timing advance amount and actual timing advance amount is calculated dur-
ing exhaust AVCS control, and the difference per predetermined time is the specified value or larger.
Judge as NG when the following conditions are established within the predetermined time.
Time Needed for Diagnosis: 25000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) AVCS timing controller (3) Engine control module (ECM) (5) Oil pressure
(2) Vane (4) Oil flow control solenoid valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Exhaust AVCS control Operation
Target timing advance change amount (per 64 ms) < 10 °CA
Judgment Value
Malfunction Criteria Threshold Value
Σ(Target position – Actual position) > 4000 °CA (Bank 1)
> 4000 °CA (Bank 2)
or
Σ(Target position – Actual position) < –4000 °CA (Bank 1)
< –4000 °CA (Bank 2)
EN-01852
(3)
(4)
(1)
(5)
(2)
15WRX_STI_US_EN.book 14 ペー   
GD(STI)-15
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
K: DTC P000C A CAMSHAFT POSITION SLOW RESPONSE (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to P000A. <Ref. to GD(STI)-13, DTC P000A A CAMSHAFT POSITION
SLOW RESPONSE (BANK 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
L: DTC P000D B CAMSHAFT POSITION SLOW RESPONSE (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to P000B. <Ref. to GD(STI)-14, DTC P000B B CAMSHAFT POSITION
SLOW RESPONSE (BANK 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
15WRX_STI_US_EN.book 15 ペー   
GD(STI)-16
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
M: DTC P0011 INTAKE CAMSHAFT POSITION - TIMING OVER-ADVANCED OR
SYSTEM PERFORMANCE (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the AVCS system malfunction.
Judge NG when the amount of AVCS actual timing advance does not approach to the amount of AVCS target
timing advance.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously while AVCS is operating.
5. DIAGNOSTIC METHOD
When the conditions during which the differences of AVCS target timing advance amount and AVCS actual
timing advance amount is large continues for certain amount of time.
Judge as NG when the following conditions are established within the predetermined time.
Time Needed for Diagnosis: 5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) AVCS timing controller (3) Engine control module (ECM) (5) Oil pressure
(2) Vane (4) Oil flow control solenoid valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
AVCS control Operation
Judgment Value
Malfunction Criteria Threshold Value
(Target position – Actual position) > 20 °CA
or
< –20 °CA
EN-01852
(3)
(4)
(1)
(5)
(2)
15WRX_STI_US_EN.book 16 ペー   
GD(STI)-17
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
N: DTC P0014 EXHAUST AVCS SYSTEM 1 (RANGE/PERFORMANCE)
1. OUTLINE OF DIAGNOSIS
Detect the exhaust AVCS system malfunction.
Judge NG when the amount of exhaust AVCS actual timing advance does not approach the amount of ex-
haust AVCS target timing advance.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously while exhaust AVCS is operating.
5. DIAGNOSTIC METHOD
When the conditions during which the differences of exhaust AVCS target timing advance amount and ex-
haust AVCS actual timing advance amount is large continues for certain amount of time.
Judge as NG when the following conditions are established within the predetermined time.
Time Needed for Diagnosis:
5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) Exhaust AVCS timing controller (3) Engine control module (ECM) (5) Oil pressure
(2) Vane (4) Oil flow control solenoid valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Exhaust AVCS control Operation
Judgment Value
Malfunction Criteria Threshold Value
(Target position – Actual position) > 20 °CA
or
< –20 °CA
EN-01852
(3)
(4)
(1)
(5)
(2)
15WRX_STI_US_EN.book 17 ペー   
GD(STI)-18
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
O: DTC P0016 CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELA-
TION (BANK1)
1. OUTLINE OF DIAGNOSIS
Detect the AVCS system malfunction.
Judge as NG when standard timing advance amount is far from learning angle.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after starting engine and while AVCS is not operating.
(1) AVCS timing controller (3) Engine control module (ECM) (5) Oil pressure
(2) Vane (4) Oil flow control solenoid valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after external load (power steering, neutral position switch) change 3000 ms
AVCS learning In operation
AVCS learning experience flag (diagnosis 1 only) Set
EN-01852
(3)
(4)
(1)
(5)
(2)
15WRX_STI_US_EN.book 18 ペー   
GD(STI)-19
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Judge as NG when the absolute value of the difference between cam signal input position and learning value
is out of specification.
Diagnosis 1
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 5000 ms
Diagnosis 2
Time Needed for Diagnosis: 5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
NOTE:
Initial standard learning value is the value of crank angle initially input at the production plant. And then it will
be updated every time normal judgment has been completed. Learning value will not be updated if NG judg-
ment occurs because timing belt or chain derails suddenly in process or because wrong assembly occurs
during servicing.
Judgment Value
Malfunction Criteria Threshold Value
|Crankshaft position when camshaft position sensor signal is input – Learning
value|
> 8.5 °CA
Judgment Value
Malfunction Criteria Threshold Value
Camshaft position sensor signal input position < 13 °CA
or
> 55 °CA
15WRX_STI_US_EN.book 19 ペー   
GD(STI)-20
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
P: DTC P0017 CRANK AND CAM TIMING B SYSTEM FAILURE (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the exhaust AVCS system malfunction.
Judge as NG when standard timing advance amount is far from learning angle.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously while the exhaust AVCS is not operating after warming up.
(1) Exhaust AVCS timing controller (3) Engine control module (ECM) (5) Oil pressure
(2) Vane (4) Oil flow control solenoid valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after external load (power steering, neutral position switch) change 3000 ms
Exhaust AVCS learning In operation
Exhaust AVCS learning experience flag (diagnosis 1 only) Set
EN-01852
(3)
(4)
(1)
(5)
(2)
15WRX_STI_US_EN.book 20 ペー   
GD(STI)-21
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Judge as NG when the absolute value of the difference between cam signal input position and learning value
is out of specification.
Diagnosis 1
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 5000 ms
Diagnosis 2
Time Needed for Diagnosis: 5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
NOTE:
Initial standard learning value is the value of crank angle initially input at the production plant. And then it will
be updated every time normal judgment has been completed. Learning value will not be updated if NG judg-
ment occurs because timing belt or chain derails suddenly in process or because wrong assembly occurs
during servicing.
Q: DTC P0018 CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELA-
TION (BANK2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0016. <Ref. to GD(STI)-18, DTC P0016 CRANKSHAFT POSITION -
CAMSHAFT POSITION CORRELATION (BANK1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
R: DTC P0019 CRANK AND CAM TIMING B SYSTEM FAILURE (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0017. <Ref. to GD(STI)-20, DTC P0017 CRANK AND CAM TIM-
ING B SYSTEM FAILURE (BANK 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
S: DTC P0021 INTAKE CAMSHAFT POSITION - TIMING OVER-ADVANCED OR
SYSTEM PERFORMANCE (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0011. <Ref. to GD(STI)-16, DTC P0011 INTAKE CAMSHAFT PO-
SITION - TIMING OVER-ADVANCED OR SYSTEM PERFORMANCE (BANK 1), Diagnostic Trouble Code
(DTC) Detecting Criteria.>
T: DTC P0024 EXHAUST AVCS SYSTEM 2 (RANGE/PERFORMANCE)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0014. <Ref. to GD(STI)-17, DTC P0014 EXHAUST AVCS SYS-
TEM 1 (RANGE/PERFORMANCE), Diagnostic Trouble Code (DTC) Detecting Criteria.>
Judgment Value
Malfunction Criteria Threshold Value
|Crankshaft position when camshaft position sensor signal is input – Learning value| > 8.5 °CA
Judgment Value
Malfunction Criteria Threshold Value
Camshaft position sensor signal input position < 55 °CA
or
> 105 °CA
15WRX_STI_US_EN.book 21 ペー   
GD(STI)-22
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
U: DTC P0030 HO2S HEATER CONTROL CIRCUIT (BANK 1 SENSOR 1)
1. OUTLINE OF DIAGNOSIS
Detect functional errors of the front oxygen (A/F) sensor heater.
Judge as NG when it is determined that the front oxygen (A/F) sensor impedance is large when looking at en-
gine status such as deceleration fuel cut.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after 42000 ms seconds or more have passed since the engine started.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 10000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) Element cover (outer) (3) Sensor element (4) Sensor housing
(2) Element cover (inner)
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
A/F sensor heater control duty > 30 %
Elapsed time after returning from the fuel cut 20000 ms
Judgment Value
Malfunction Criteria Threshold Value
Front oxygen (A/F) sensor impedance > 35 Ω
EN-08982
(1) (2) (3)
(4)
15WRX_STI_US_EN.book 22 ペー   
GD(STI)-23
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
V: DTC P0031 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)
1. OUTLINE OF DIAGNOSIS
Detect front oxygen (A/F) sensor heater open or short circuit.
The front oxygen (A/F) sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and
the output terminal voltage at OFF is the battery voltage.
Judge as NG when the terminal voltage remains Low.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 4 ms × 250 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Battery voltage (B) Front oxygen (A/F) sensor heater
output voltage
(C) 128 ms
(D) Low error
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Front oxygen (A/F) sensor heater control duty < 87.5 %
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 1.9 V
EN-01792
(C)
(A)
(B)
ON
OFF
0V
(D)
15WRX_STI_US_EN.book 23 ペー   
GD(STI)-24
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
W: DTC P0032 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 1)
1. OUTLINE OF DIAGNOSIS
Detect front oxygen (A/F) sensor heater open or short circuit.
The front oxygen (A/F) sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and
the output terminal voltage at OFF is the battery voltage.
Judge as NG when the terminal voltage remains High.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 4 ms × 500 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Battery voltage (B) Front oxygen (A/F) sensor heater
output voltage
(C) 128 ms
(D) High error
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Front oxygen (A/F) sensor heater control duty 12.5 %
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 1.9 V
EN-01793
(C)
(A)
(B)
ON
OFF
0V
(D)
15WRX_STI_US_EN.book 24 ペー   
GD(STI)-25
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
X: DTC P0037 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the rear oxygen sensor heater open or short circuit.
The rear oxygen sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and the
output terminal voltage at OFF is the battery voltage.
Judge as NG when the terminal voltage remains Low.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
After starting the engine, perform the diagnosis continuously when engine is low speed.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 8 ms × 1250 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) Battery voltage (B) Output voltage of the rear oxygen
sensor heater
(C) 256 ms (cycles)
(D) Low error
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after engine starting 1 s
Rear oxygen sensor heater control duty < 75 %
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < Battery voltage × 0.2 V
EN-01792
(C)
(A)
(B)
ON
OFF
0V
(D)
15WRX_STI_US_EN.book 25 ペー   
GD(STI)-26
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Y: DTC P0038 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the rear oxygen sensor heater open or short circuit.
The rear oxygen sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and the
output terminal voltage at OFF is the battery voltage.
Judge as NG when the terminal voltage remains High.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
After starting the engine, perform the diagnosis continuously when engine is low speed.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 8 ms × 320 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) Battery voltage (B) Output voltage of the rear oxygen
sensor heater
(C) 256 ms (cycles)
(D) High error
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after engine starting 1 s
Rear oxygen sensor heater control duty 25 %
Judgment Value
Malfunction Criteria Threshold Value
Output voltage > Battery voltage × 0.3 V
EN-01793
(C)
(A)
(B)
ON
OFF
0V
(D)
15WRX_STI_US_EN.book 26 ペー   
GD(STI)-27
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Z: DTC P0068 MAP/MAF - THROTTLE POSITION CORRELATION
1. OUTLINE OF DIAGNOSIS
Detect problems in the intake manifold pressure sensor output properties.
Judge as NG when the intake air pressure AD value is Low whereas it seemed to be High from the viewpoint
of engine condition, or when it is High whereas it seemed to be Low from the engine condition.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after idling.
(A) Output voltage (B) Absolute pressure
(1) Connector (2) Terminals (3) O-ring
Low
Secondary Parameters Enable Conditions
Engine coolant temperature 70 °C (158 °F)
Engine speed < 2700 rpm
Charging efficiency > 0.45 g/rev (0.02 oz/rev)
Throttle position 10 °
High
Secondary Parameters Enable Conditions
Engine coolant temperature 70 °C (158 °F)
Engine speed 600 rpm
and
< 900 rpm
Charging efficiency 0.4 g/rev (0.01 oz/rev)
Throttle position 2.75 °
EN-01765
(B)
(A)
(2)
(3)
(1)
15WRX_STI_US_EN.book 27 ペー   
GD(STI)-28
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Judge as NG when Low side or High side becomes NG.
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis:
Low side: 5000 ms
High side: 5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Low
Output voltage < 0.764 V
High
Output voltage 2.126 V
15WRX_STI_US_EN.book 28 ペー   
GD(STI)-29
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AA:DTC P0071 AMBIENT TEMPERATURE SENSOR CIRCUIT "A" RANGE/PER-
FORMANCE
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of ambient temperature sensor characteristics.
After the engine starts after the specified period of soaking time has elapsed, judge by correlation between
ambient temperature sensor value, intake air temperature sensor value and engine coolant temperature sen-
sor value. Judge as NG when the differences are both above the specified value by comparing between am-
bient air temperature and intake air temperature, ambient air temperature and engine coolant temperature.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after the engine starts after a certain period of soaking time.
(1) Ambient temperature sensor (2) Resistance value (kΩ) (3) Ambient air temperature (°C (°F))
Secondary Parameters Enable Conditions
Soaking time 21600 s
Block heater judgment Completed
Block heater operation Not in operation
EN-10816
(2)
(3)
(1)
15WRX_STI_US_EN.book 29 ペー   
GD(STI)-30
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 64 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
|Ambient air temperature 30 sec. after engine start – Intake air temperature 30
sec. after engine start|
> Value from Map
|Ambient air temperature at engine start – Engine coolant temperature at engine
start|
> 25 °C (45°F)
Map
Ambient air temperature
°C (°F)
–30
(–22)
30
(86)
45
(113)
60
(140)
|Ambient air temperature 30 sec. after engine start – Intake air
temperature 30 sec. after engine start|
°C (°F)
20
(36°F)
20
(36°F)
32
(57.6°F)
32
(57.6°F)
15WRX_STI_US_EN.book 30 ペー   
GD(STI)-31
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AB:DTC P0072 AMBIENT TEMPERATURE SENSOR CIRCUIT "A" LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of ambient temperature sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Ambient temperature sensor (2) Resistance value (kΩ) (3) Ambient air temperature (°C (°F))
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.42 V
EN-10816
(2)
(3)
(1)
15WRX_STI_US_EN.book 31 ペー   
GD(STI)-32
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AC:DTC P0073 AMBIENT TEMPERATURE SENSOR CIRCUIT "A" HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of ambient temperature sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Ambient temperature sensor (2) Resistance value (kΩ) (3) Ambient air temperature (°C (°F))
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Output voltage > 4.88 V
EN-10816
(2)
(3)
(1)
15WRX_STI_US_EN.book 32 ペー   
GD(STI)-33
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AD:DTC P0101 MASS OR VOLUME AIR FLOW CIRCUIT RANGE/PERFOR-
MANCE
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of air flow sensor output properties.
Judge as a low side NG when the air flow voltage indicates a small value regardless of running in a state
where the air flow voltage increases. Judge as a high side NG when the air flow voltage indicates a large val-
ue regardless of running in a state where the air flow voltage decreases. Judge air flow sensor property NG
when the Low side or High side becomes NG.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after idling.
(A) Air
(1) Air flow sensor (3) Voltage (V) (4) Amount of intake air (kg (lb)/s)
(2) Intake air temperature sensor
Low
Secondary Parameters Enable Conditions
Engine speed 1800 rpm
Throttle opening angle 10 °
Engine coolant temperature 70 °C (158 °F)
Intake manifold pressure 53.3 kPa (400 mmHg, 15.7 inHg)
High
Secondary Parameters Enable Conditions
Engine speed 600 rpm
and
< 900 rpm
Throttle opening angle < 4.1 °
Engine coolant temperature 70 °C (158 °F)
Intake manifold pressure < 52.7 kPa (395 mmHg, 15.6 inHg)
EN-01766
(3)
(4)
(2)
(1)
(A)
15WRX_STI_US_EN.book 33 ペー   
GD(STI)-34
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Judge as NG when Low side or High side becomes NG.
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis:
Low: 5000 ms
High: 5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Low
Output voltage < 1.2 V
High
Output voltage 1.95 V
15WRX_STI_US_EN.book 34 ペー   
GD(STI)-35
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AE:DTC P0102 MASS OR VOLUME AIR FLOW CIRCUIT LOW INPUT
1. OUTLINE OF DIAGNOSIS
Detect open or short circuits of the air flow sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Air
(1) Air flow sensor (3) Voltage (V) (4) Amount of intake air (kg (lb)/s)
(2) Intake air temperature sensor
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.22 V
EN-01766
(3)
(4)
(2)
(1)
(A)
15WRX_STI_US_EN.book 35 ペー   
GD(STI)-36
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AF:DTC P0103 MASS OR VOLUME AIR FLOW CIRCUIT HIGH INPUT
1. OUTLINE OF DIAGNOSIS
Detect open or short circuits of the air flow sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Air
(1) Air flow sensor (3) Voltage (V) (4) Amount of intake air (kg (lb)/s)
(2) Intake air temperature sensor
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.952 V
EN-01766
(3)
(4)
(2)
(1)
(A)
15WRX_STI_US_EN.book 36 ペー   
GD(STI)-37
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AG:DTC P0107 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE
CIRCUIT LOW INPUT
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of intake manifold pressure sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Output voltage (B) Absolute pressure
(1) Connector (2) Terminals (3) O-ring
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.581 V
EN-01765
(B)
(A)
(2)
(3)
(1)
15WRX_STI_US_EN.book 37 ペー   
GD(STI)-38
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AH:DTC P0108 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE
CIRCUIT HIGH INPUT
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of intake manifold pressure sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Output voltage (B) Absolute pressure
(1) Connector (2) Terminals (3) O-ring
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.681 V
EN-01765
(B)
(A)
(2)
(3)
(1)
15WRX_STI_US_EN.book 38 ペー   
GD(STI)-39
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AI: DTC P0111 INTAKE AIR TEMPERATURE SENSOR RANGE/PERFORMANCE
PROBLEM
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of the intake air temperature sensor output properties. Using the following two diag-
noses, judge as NG when either is NG.
Diagnosis 1 (correlation diagnosis): After the engine starts after the specified period of soaking time has
elapsed, diagnose by correlation between intake air temperature sensor value, engine coolant temperature
sensor value and ambient temperature sensor value. Judge as NG when the differences are both above the
specified value by comparing between intake air temperature and engine coolant temperature, intake air
temperature and ambient air temperature.
Diagnosis 2 (stuck diagnosis): Judge as NG when intake air temperature does not change under the
driving condition where it should change, considering engine condition.
2. COMPONENT DESCRIPTION
(A) Air
(1) Intake air temperature sensor (2) Resistance value (Ω) (3) Intake air temperature °C (°F)
(A)
(1)
(2)
(3)
EN-10604
15WRX_STI_US_EN.book 39 ペー   
GD(STI)-40
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
Diagnosis 1
Diagnosis 2
4. GENERAL DRIVING CYCLE
Diagnosis 1: Perform the diagnosis only once after the engine starts after a certain period of soaking time.
Diagnosis 2: Perform the diagnosis when the vehicle speed condition is met after warming up from a cold
condition.
Secondary Parameters Enable Conditions
Soaking time 21600 s
Block heater judgment Completed
Block heater operation Not in operation
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Engine coolant temperature 70 °C (158 °F)
Intake air amount sum value Value of Map 1
Number of experiences under conditions below 3 time(s)
• Continuous time when vehicle speed is less than 4 km/h (2.5 MPH) Value from Map 2
• Continuous time when vehicle speed is 40 km/h (24.9 MPH) or more, and
intake air amount is 15 g/s (0.53 oz/s) or more
15 s
Map 1
Engine coolant temperature
°C (°F)
–20
(–4)
–10
(14)
0
(32)
10
(50)
20
(68)
Intake air amount sum value (g (oz)) 76000 (2680.52) 10192 (359.47) 9028 (318.42) 7864 (277.36) 7000 (246.89)
Map 2
Engine coolant temperature
°C (°F)
–20
(–4)
–10
(14)
5
(41)
20
(68)
Continuous time (s) when vehicle speed is
less than 4 km/h (2.5 MPH)
250403224
15WRX_STI_US_EN.book 40 ペー   
GD(STI)-41
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Judge as NG when Diagnosis 1 or Diagnosis 2 becomes NG.
Diagnosis 1
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 64 ms
Diagnosis 2
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Less than 1 second
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
|Intake air temperature 30 sec. after engine start – Engine coolant temperature at engine start| > Value of Map 3
|Intake air temperature 30 sec. after engine start – Ambient air temperature 30 sec. after engine start| > Value of Map 4
Map 3
Ambient air temperature
°C (°F)
–30
(–22)
30
(86)
45
(113)
60
(140)
|Intake air temperature 30 sec. after engine start –
Engine coolant temperature at engine start|
°C (°F)
12
(21.6°F)
12
(21.6°F)
22
(39.6°F)
22
(39.6°F)
Map 4
Ambient air temperature
°C (°F)
–30
(–22)
30
(86)
45
(113)
60
(140)
|Intake air temperature 30 sec. after engine start –
Ambient air temperature 30 sec. after engine start|
°C (°F)
20
(36°F)
20
(36°F)
32
(57.6°F)
32
(57.6°F)
Judgment Value
Malfunction Criteria Threshold Value
Output voltage difference between Max. and Min. < 0.02 V (Equivalent to approximately 0.5°C (0.9°F) near 25°C (77°F))
15WRX_STI_US_EN.book 41 ペー   
GD(STI)-42
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AJ:DTC P0112 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the intake air temperature sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Air
(1) Air flow sensor (3) Resistance value (Ω) (4) Intake air temperature °C (°F)
(2) Intake air temperature sensor
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.395 V
EN-01767
(3)
(4)
(2)
(1)
(A)
15WRX_STI_US_EN.book 42 ペー   
GD(STI)-43
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AK:DTC P0113 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the intake air temperature sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Air
(1) Air flow sensor (3) Resistance value (Ω) (4) Intake air temperature °C (°F)
(2) Intake air temperature sensor
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.712 V
EN-01767
(3)
(4)
(2)
(1)
(A)
15WRX_STI_US_EN.book 43 ペー   
GD(STI)-44
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AL:DTC P0116 ENGINE COOLANT TEMPERATURE SENSOR 1 CIRCUIT
RANGE/PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of the engine coolant temperature sensor characteristics.
After the engine starts after the specified period of soaking time has elapsed, diagnose by correlation be-
tween engine coolant temperature sensor value, intake air temperature sensor value and ambient tempera-
ture sensor value. Judge as NG when the differences are both above the specified value by comparing
between engine coolant temperature and ambient air temperature, engine coolant temperature and intake air
temperature.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after the engine starts after a certain period of soaking time.
(A) Resistance value (kΩ) (B) Temperature °C (°F)
(1) Connector (2) Thermistor element
Secondary Parameters Enable Conditions
Soaking time 21600 s
Block heater judgment Completed
Block heater operation Not in operation
EN-02917
(A)
(2)
(1)
(B)
15WRX_STI_US_EN.book 44 ペー   
GD(STI)-45
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 64 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
|Engine coolant temperature at engine start – Intake air temperature 30 sec. after engine start| > Value from Map
|Engine coolant temperature at engine start – Ambient air temperature at engine start| > 25 °C (45°F)
Map
Ambient air temperature
°C (°F)
–30
(–22)
30
(86)
45
(113)
60
(140)
|Engine coolant temperature at engine start – Intake air tem-
perature 30 sec. after engine start|
°C (°F)
12
(21.6°F)
12
(21.6°F)
22
(39.6°F)
22
(39.6°F)
15WRX_STI_US_EN.book 45 ペー   
GD(STI)-46
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AM:DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the engine coolant temperature sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Resistance value (kΩ) (B) Temperature °C (°F)
(1) Connector (2) Thermistor element
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.343 V
EN-02917
(A)
(2)
(1)
(B)
15WRX_STI_US_EN.book 46 ペー   
GD(STI)-47
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AN:DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the engine coolant temperature sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Resistance value (kΩ) (B) Temperature °C (°F)
(1) Connector (2) Thermistor element
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.702 V
EN-02917
(A)
(2)
(1)
(B)
15WRX_STI_US_EN.book 47 ペー   
GD(STI)-48
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AO:DTC P0122 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT
LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of throttle position sensor 1.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 24 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Throttle position sensor 1 signal (3) Throttle position sensor (4) Engine control module (ECM)
(2) Throttle position sensor 2 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 1 input voltage 0.27 V
EN-01859
(1)
(2)
(3)
(4)
15WRX_STI_US_EN.book 48 ペー   
GD(STI)-49
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AP:DTC P0123 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT
HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of throttle position sensor 1.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 24 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Throttle position sensor 1 signal (3) Throttle position sensor (4) Engine control module (ECM)
(2) Throttle position sensor 2 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 1 input voltage 4.858 V
EN-01859
(1)
(2)
(3)
(4)
15WRX_STI_US_EN.book 49 ペー   
GD(STI)-50
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AQ:DTC P0125 INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP
FUEL CONTROL
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of engine coolant temperature output property.
Judge as NG when engine coolant temperature does not rise to the specified value after predetermined time
has elapsed since engine start.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after starting the engine from cold condition.
(A) Resistance value (kΩ) (B) Temperature °C (°F)
(1) Connector (2) Thermistor element
Secondary Parameters Enable Conditions
Engine coolant temperature at engine start < –15 °C (5 °F)
Engine speed > 500 rpm
EN-02917
(A)
(2)
(1)
(B)
15WRX_STI_US_EN.book 50 ペー   
GD(STI)-51
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 120 or 300 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Engine coolant temperature < –15 °C (5 °F)
Elapsed time after starting the engine
((Smaller value either one of engine coolant temperature and intake air temperature at engine start)
–23.3°C (–9.9°F))
or
((Smaller value either one of engine coolant temperature and intake air temperature at engine start)
< –23.3°C (–9.9°F))
Value from Map
Map
Smaller value either one of engine coolant temperature and intake air temperature
at engine start
°C (°F)
–40
(–40)
–23.4
(–10.1)
–23.3
(–9.9)
0
(32)
20
(68)
40
(104)
60
(140)
80
(176)
Percentage of time when engine is
at stop against time elapsed since
engine start
0.0 300000 300000 120000 120000 120000 120000 120000 120000
0.3 300000 300000 120000 120000 120000 120000 120000 120000
0.6 300000 300000 120000 120000 120000 120000 120000 120000
1.0 300000 300000 120000 120000 120000 120000 120000 120000
ms
15WRX_STI_US_EN.book 51 ペー   
GD(STI)-52
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AR:DTC P0128 COOLANT THERMOSTAT (ENGINE COOLANT TEMPERATURE
BELOW THERMOSTAT REGULATING TEMPERATURE)
1. OUTLINE OF DIAGNOSIS
Detect malfunctions of the thermostat function.
Judge as NG when any one of the following conditions is established.
When the actual engine coolant temperature does not reach the maximum temperature necessary to per-
form other OBDII diagnosis and Σ (Estimated engine coolant temperature – actual engine coolant tempera-
ture) exceeded the predetermined value. (Judgment 1)
When the actual engine coolant temperature does not reach the range within –11°C (–19.8°F) from the
regulated temperature and Σ (Estimated engine coolant temperature – actual engine coolant temperature)
exceeded the predetermined value. (Judgment 2)
When the difference between the estimated coolant temperature and the actual engine coolant tempera-
ture exceeds the predetermined value, and Σ (Estimated engine coolant temperature – actual engine coolant
temperature) exceeded the predetermined value. (Judgment 3)
2. COMPONENT DESCRIPTION
(1) Valve (4) Piston (7) Stop ring
(2) Spring (5) Guide (8) Wax element
(3) Stopper (6) Rubber seal (9) Jiggle valve
EN-01692
(9)
(2)
(6)
(8)
(7)
(5)
(4)
(3)
(1)
(2)
15WRX_STI_US_EN.book 52 ペー   
GD(STI)-53
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after starting the engine.
Secondary Parameters Enable Conditions
<Judgment 1>
Battery voltage 10.9 V
Ambient air temperature –7 °C (19.4 °F)
Vehicle speed 30 km/h (18.6 MPH)
Estimated coolant temperature > Value of Map 1
Engine coolant temperature at engine start < 60 °C (140 °F)
<Judgment 2>
Battery voltage 10.9 V
Ambient air temperature –7 °C (19.4 °F)
Vehicle speed 30 km/h (18.6 MPH)
Estimated coolant temperature > Value of Map 2
Engine coolant temperature at engine start < 60 °C (140 °F)
<Judgment 3>
Battery voltage 10.9 V
Ambient air temperature –7 °C (19.4 °F)
Vehicle speed 30 km/h (18.6 MPH)
Estimated coolant temperature Value from Map 3
Engine coolant temperature at engine start < 60 °C (140 °F)
Map 1
Engine coolant temperature at engine starting
°C (°F)
–7
(19.4)
8
(46.4)
10
(50)
25
(77)
Estimated coolant temperature
°C (°F)
70
(158)
70
(158)
70
(158)
70
(158)
Map 2
Engine coolant temperature at engine starting
°C (°F)
–7
(19.4)
8
(46.4)
10
(50)
25
(77)
Estimated coolant temperature
°C (°F)
77.5
(171.5)
77.5
(171.5)
77.5
(171.5)
77.5
(171.5)
Map 3
Engine coolant temperature at engine starting
°C (°F)
–7
(19.4)
10
(50)
26
(78.8)
60
(140)
Estimated coolant temperature
°C (°F)
60
(140)
69
(156.2)
77.5
(171.5)
77.5
(171.5)
15WRX_STI_US_EN.book 53 ペー   
GD(STI)-54
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Judgment Value
Malfunction Criteria Threshold Value
When any one of the followings is established:
<Judgment 1>
Actual engine coolant temperature < Value of Map 4
and
Σ (Estimated engine coolant temperature – actual engine coolant temperature) > Value of Map 5
<Judgment 2>
Actual engine coolant temperature < Regulated temperature – Value of Map 6
and
Σ (Estimated engine coolant temperature – actual engine coolant temperature) > Value of Map 7
<Judgment 3>
Estimated engine coolant temperature – actual engine coolant temperature > Value of Map 8
and
Σ (Estimated engine coolant temperature – actual engine coolant temperature) > Value of Map 9
Map 4
Estimate ambient temperature
°C (°F)
–7
(19.4)
8
(46.4)
10
(50)
25
(77)
Threshold Value
°C (°F)
70
(158)
70
(158)
70
(158)
70
(158)
Map 5
Engine coolant temperature at
engine starting
°C (°F)
–7
(19.4)
0
(32)
8
(46.4)
10
(50)
25
(77)
35
(95)
Threshold Value
°C (°F)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1200
(1800)
Map 6
Estimate ambient temperature
°C (°F)
–7
(19.4)
8
(46.4)
10
(50)
25
(77)
Threshold Value
°C (°F)
11.1
(20)
11.1
(20)
11.1
(20)
11.1
(20)
Map 7
Engine coolant temperature at
engine starting
°C (°F)
–7
(19.4)
0
(32)
8
(46.4)
10
(50)
25
(77)
30
(86)
35
(95)
Threshold Value
°C (°F)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1200
(2160)
Map 8
Estimate ambient temperature
°C (°F)
–7
(19.4)
8
(46.4)
10
(50)
25
(77)
Threshold Value
°C (°F)
11.1
(20)
11.1
(20)
11.1
(20)
11.1
(20)
15WRX_STI_US_EN.book 54 ペー   
GD(STI)-55
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Time Needed for Diagnosis: 300 — 700 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Map 9
Engine coolant temperature at engine starting
°C (°F)
–7
(19.4)
8
(46.4)
10
(50)
25
(77)
Threshold Value
°C (°F)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
1731.6
(3116.9)
15WRX_STI_US_EN.book 55 ペー   
GD(STI)-56
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AS:DTC P0131 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 1)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of sensor.
Judge as NG, when the element voltage is out of the specified range.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Electromotive force (B) Air fuel ratio (C) Rich
(D) Lean
(1) Exhaust gas (2) ZrO
2
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Input voltage (+) < 1.128 V
or
Input voltage (–) < 0.644 V
or
|Input voltage (+) – Input voltage (–)| < 0.23 V
EN-09361
(C) (B) (D)
(A)
(2)
(1)(1)
15WRX_STI_US_EN.book 56 ペー   
GD(STI)-57
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AT:DTC P0132 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 1)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of sensor.
Judge as NG, when the element voltage is out of the specified range.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Electromotive force (B) Air fuel ratio (C) Rich
(D) Lean
(1) Exhaust gas (2) ZrO
2
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Input voltage (+) > 3.589 V
or
Input voltage (–) > 3.541 V
EN-09361
(C) (B) (D)
(A)
(2)
(1)(1)
15WRX_STI_US_EN.book 57 ペー   
GD(STI)-58
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AU:DTC P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SEN-
SOR 1)
1. OUTLINE OF DIAGNOSIS
Detect open circuits of the sensor.
Judge as NG when the impedance of the element is large.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 5000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) Electromotive force (B) Air fuel ratio (C) Rich
(D) Lean
(1) Exhaust gas (2) ZrO
2
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Time of heater control duty at 70 % or more 36000 ms
Judgment Value
Malfunction Criteria Threshold Value
Front oxygen (A/F) sensor impedance > 500 Ω
EN-09361
(C) (B) (D)
(A)
(2)
(1)(1)
15WRX_STI_US_EN.book 58 ペー   
GD(STI)-59
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AV:DTC P0137 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect continuity NG of the oxygen sensor. If the oxygen sensor voltage reading is not within the probable
range considering the operating conditions, judge as NG.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
After starting the engine, continuously perform the diagnosis with the same engine condition.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
(1) Atmosphere (2) Exhaust gas (3) Electromotive force
Secondary Parameters Enable Conditions
High
Battery voltage 10.9 V
Low (1)
Battery voltage 10.9 V
Closed loop control at the oxygen sensor In operation
Secondary air system Not in operation
Amount of intake air 10 g/s (0.35 oz/s)
Low (2)
Battery voltage 10.9 V
Closed loop control at the oxygen sensor In operation
Secondary air system Not in operation
Amount of intake air < 10 g/s (0.35 oz/s)
EN-01696
(3)
V
(1)
(2) (2)
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 59 ペー   
GD(STI)-60
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis:
High: 2500 ms
Low (1): 20000 ms
Low (2): 150000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
AW:DTC P0138 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0137. <Ref. to GD(STI)-59, DTC P0137 O2 SENSOR CIRCUIT
LOW VOLTAGE (BANK 1 SENSOR 2), Diagnostic Trouble Code (DTC) Detecting Criteria.>
Judgment Value
Malfunction Criteria Threshold Value DTC
High P0138
Sensor output voltage > 1.2 V
Low P0137
Sensor output voltage < 0.03 V
15WRX_STI_US_EN.book 60 ペー   
GD(STI)-61
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AX:DTC P013A O2 SENSOR SLOW RESPONSE - RICH TO LEAN (BANK 1 SEN-
SOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the slow response of rich lean for rear oxygen sensor output.
When the deceleration fuel cut has occurred, detect the trouble by calculating the time when the rear oxygen
sensor output passes through the predetermined range of voltages.
Judge as NG when the response time is larger than the threshold value.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform diagnosis once during deceleration fuel cut from a constant and high speed driving, when rear oxy-
gen sensor is warmed up sufficiently.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
(1) Atmosphere (2) Exhaust gas (3) Electromotive force
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Current calculation time of the rear oxygen sensor heater after starting 180000 ms
Rear oxygen sensor voltage when fuel cut starts 0.55 V
Fuel cut In operation
Estimated temperature of rear oxygen sensor element when fuel cut starts 500 °C (932 °F)
EN-01696
(3)
V
(1)
(2) (2)
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 61 ペー   
GD(STI)-62
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Detect the trouble by calculating the response time of the rear oxygen sensor during fuel cut.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) 0.55 V (B) 0.50 V (C) 0.20 V
(D) 0.15 V (E) 0 V (F) Diagnostic parameter
(G) Normal (H) Malfunction
Judgment Value
Malfunction Criteria Threshold Value
Time needed for rear oxygen sensor voltage to change from 0.5 V to 0.2 V > 837 ms
EN-09344
(H)
(E)
(D)
(C)
(B)
(A)
Rear oxygen sensor (V)
Fuel cut on deceleration
(F)
(G)
15WRX_STI_US_EN.book 62 ペー   
GD(STI)-63
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AY:DTC P013B O2 SENSOR SLOW RESPONSE - LEAN TO RICH (BANK 1 SEN-
SOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the slow response of lean rich for rear oxygen sensor output.
After the deceleration fuel cut has occurred, detect the trouble by calculating the time when the rear oxygen
sensor output passes through the predetermined range of voltages.
Judge as NG when the response time is larger than the threshold value.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform diagnosis only once after recovering from a deceleration fuel cut continued for more than predeter-
mined time.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
(1) Atmosphere (2) Exhaust gas (3) Electromotive force
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Front oxygen (A/F) sensor closed loop control Operation
Fuel cut time 5000 ms
EN-01696
(3)
V
(1)
(2) (2)
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 63 ペー   
GD(STI)-64
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Detect the trouble by calculating the response time of the rear oxygen sensor after fuel cut.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 4000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) 0.55 V (B) 0.50 V (C) 0.30 V
(D) 0.25 V (E) 0 V (F) Diagnostic parameter
(G) Normal (H) Malfunction
Judgment Value
Malfunction Criteria Threshold Value
Time when rear oxygen sensor voltage changed from 0.3 V to 0.5 V > 4000 ms
(H)
(D)
(C)
EN-09345
(E)
(B)
(A)
Rear oxygen sensor (V)
Fuel cut on deceleration
(F)
(G)
15WRX_STI_US_EN.book 64 ペー   
GD(STI)-65
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AZ:DTC P013E O2 SENSOR DELAYED RESPONSE - RICH TO LEAN (BANK 1
SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the delayed response of rear oxygen sensor output for rich lean.
After the deceleration fuel cut has started, detect the trouble by calculating the time when the rear oxygen
sensor output decreases to the predetermined voltages.
Judge as NG when the response time is larger than the threshold value.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform diagnosis once during deceleration fuel cut from a constant and high speed driving, when rear oxy-
gen sensor is warmed up sufficiently.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
(1) Atmosphere (2) Exhaust gas (3) Electromotive force
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Rear oxygen sensor voltage when fuel cut starts 0.55 V
Fuel cut In operation
Estimated temperature of rear oxygen sensor element when fuel cut starts 500 °C (932 °F)
Fuel injection increase amount of exhaust system protection = 0
EN-01696
(3)
V
(1)
(2) (2)
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 65 ペー   
GD(STI)-66
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Detect the trouble by calculating the time from the beginning of the fuel cut to the beginning of the rear oxy-
gen sensor voltage starting to drop.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 5000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) 0.5 V (B) 0 V (C) Diagnostic parameter
(D) Normal (E) Malfunction
Judgment Value
Malfunction Criteria Threshold Value
Time when rear oxygen sensor voltage changed to 0.5 V after the fuel cut started > 4000 ms
(E)
EN-09346
(B)
(A)
Rear oxygen sensor (V)
Fuel cut on deceleration
(D)
(C)
15WRX_STI_US_EN.book 66 ペー   
GD(STI)-67
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BA:DTC P013F O2 SENSOR DELAYED RESPONSE - LEAN TO RICH (BANK 1
SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the delayed response of rear oxygen sensor output for lean rich.
After the deceleration fuel cut has completed, detect the trouble by calculating the time when the rear oxygen
sensor output increases to the predetermined voltages.
Judge as NG when the response time is larger than the threshold value.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform diagnosis only once when recovering from the deceleration fuel cut continued for more than prede-
termined time with the rear oxygen sensor warmed up sufficiently.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
(1) Atmosphere (2) Exhaust gas (3) Electromotive force
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Front oxygen (A/F) sensor closed loop control Operation
Rear oxygen sensor voltage when fuel cut has completed 0.15 V
Fuel cut time 5000 ms
Estimated element temperature of rear oxygen sensor when fuel cut has completed 500 °C (932 °F)
EN-01696
(3)
V
(1)
(2) (2)
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 67 ペー   
GD(STI)-68
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Detect the trouble by calculating the time from the completion of the fuel cut to the beginning of the rear ox-
ygen sensor voltage starting to rise.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 3750 time(s) × 32/1000
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) 0.3 V (B) 0 V (C) Diagnostic parameter
(D) Normal (E) Malfunction
Judgment Value
Malfunction Criteria Threshold Value
The number of times that the rear oxygen sensor voltage changed to 0.3 V after the fuel cut has com-
pleted (time counter)
> 3750 time(s)
(E)
(A)
EN-09347
(B)
Rear oxygen sensor (V)
Fuel cut on deceleration
(D)
(C)
15WRX_STI_US_EN.book 68 ペー   
GD(STI)-69
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BB:DTC P0141 O2 SENSOR HEATER CIRCUIT (BANK1 SENSOR2)
1. OUTLINE OF DIAGNOSIS
Detect malfunction of the rear oxygen sensor heater.
Judge as NG if it is determined that the rear oxygen sensor impedance is large by observing the engine con-
ditions.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after 1000 ms seconds or more have passed since the engine started.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 4 ms × 2500 time(s)
(1) Element cover (outer) (3) Sensor element (5) Sensor housing
(2) Element cover (inner) (4) Ceramic heater
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 1000 ms
A/F sensor element impedance 35 Ω
A/F sensor heater control duty 75 %
Rear oxygen sensor heater control duty < 75 %
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < Battery voltage × 0.88 V
EN-01683
(1) (2) (3) (4)
(5)
15WRX_STI_US_EN.book 69 ペー   
GD(STI)-70
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BC:DTC P014C O2 SENSOR SLOW RESPONSE - RICH TO LEAN (BANK 1 SEN-
SOR 1)
1. OUTLINE OF DIAGNOSIS
Detect the slow response of front oxygen (A/F) sensor.
For diagnosis, detect the trouble by processing the λ waveform in normal driving without forcibly changing
the target air fuel ratio.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform diagnosis only once in a city driving including normal acceleration and deceleration.
(A) Electromotive force (B) Air fuel ratio (C) Rich
(D) Lean
(1) Exhaust gas (2) ZrO
2
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Closed loop control with main feedback (3000 ms or more) Operation
Engine speed 1000 rpm
Amount of intake air 10 g/s (0.35 oz/s)
EN-09361
(C) (B) (D)
(A)
(2)
(1)(1)
15WRX_STI_US_EN.book 70 ペー   
GD(STI)-71
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD 1
Detect the malfunction by checking “Cumulative value of time when λ changes from lean rich” in compar-
ison to “Time during which diagnosis is in progress”.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 90000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) Time during which diagnosis is in
progress
(B) Cumulative value of time when λ
changes from lean rich
Judgment Value
Malfunction Criteria Threshold Value DTC
(Cumulative value of time when λ changes from lean rich) /
(Time during which diagnosis is in progress)
< 0.42 P014C
> 0.56 P014D
EN-09340
time
Rich
Lean
(Sensor output)
Accumulated time
(B)
(A)
15WRX_STI_US_EN.book 71 ペー   
GD(STI)-72
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
6. DIAGNOSTIC METHOD 2
Detect the malfunction by the cumulative value obtained from the amount of variation in λ change.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 90000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
BD:DTC P014D O2 SENSOR SLOW RESPONSE - LEAN TO RICH (BANK 1 SEN-
SOR 1)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P014C. <Ref. to GD(STI)-70, DTC P014C O2 SENSOR SLOW RE-
SPONSE - RICH TO LEAN (BANK 1 SENSOR 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
(Sensor output)
EN-09341
n-2
n
n-1
Judgment Value
Malfunction Criteria Threshold Value DTC
Cumulative value obtained from the amount of variation in λ change
Σ |(lambda(n) – lambda(n-1)) – (lambda(n-1) – lambda(n-2))|
< Value from Map P014C and P014D
Map
Cumulative value obtained from the amount of variation in λ
Σ |lambda(n) – lambda(n-1)|
0.00 6.00
Cumulative value obtained from the amount of variation in λ change 0.00 6.50
15WRX_STI_US_EN.book 72 ペー   
GD(STI)-73
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BE:DTC P015A O2 SENSOR DELAYED RESPONSE - RICH TO LEAN (BANK 1
SENSOR 1)
1. OUTLINE OF DIAGNOSIS
Detect the slow response of front oxygen (A/F) sensor.
For diagnosis, detect the trouble by processing the λ waveform in normal driving without forcibly changing
the target air fuel ratio.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
(A) Electromotive force (B) Air fuel ratio (C) Rich
(D) Lean
(1) Exhaust gas (2) ZrO
2
Diagnostic method 1 and 2
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Closed loop control with main feedback (3000 ms or more) Operation
Engine speed 1000 rpm
Amount of intake air 10 g/s (0.35 oz/s)
Diagnostic method 3
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Closed loop control with main feedback Operation
Vehicle speed > 40 km/h (24.9 MPH)
Engine speed 1000 rpm
and
< 4000 rpm
Amount of intake air 10 g/s (0.35 oz/s)
and
< 40 g/s (1.41 oz/s)
Catalyst depletion diagnosis Not under diagnosis
EN-09361
(C) (B) (D)
(A)
(2)
(1)(1)
15WRX_STI_US_EN.book 73 ペー   
GD(STI)-74
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
4. GENERAL DRIVING CYCLE
Perform diagnosis only once in a city driving including normal acceleration and deceleration.
5. DIAGNOSTIC METHOD 1
Detect the malfunction depending on the average value of time necessary for λ to inverse the air fuel ratio
from “Lean Rich Lean” to “Rich Lean Rich”.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 50 times of inversion
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value DTC
Average value of time necessary for λ to inverse the air fuel ratio to Lean Rich Lean > 100 ms P015A
Average value of time necessary for λ to inverse the air fuel ratio to Rich Lean Rich > 200 ms P015B
EN-09342
time
Rich
Lean
(Sensor output)
15WRX_STI_US_EN.book 74 ペー   
GD(STI)-75
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
6. DIAGNOSTIC METHOD 2
Detect the malfunction by calculating the average amplitude of λ.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 11250 time(s) × 8 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value DTC
Average value for λ amplitude > 0.1 P015A and P015B
EN-09343
time
Rich
Lean
Amplitude
(Sensor output)
15WRX_STI_US_EN.book 75 ペー   
GD(STI)-76
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
7. DIAGNOSTIC METHOD 3
Change STFT (A/F compensation value) by interruption, and measure the reaction time of λ value. When A/
F sensor malfunctions, the reaction time takes longer than at normal condition. In this case, judge as abnor-
mal.
EN-09890
Time
Lean
Rich
Lean
Rich
STFT
Response time
Time
Sensor output
15WRX_STI_US_EN.book 76 ペー   
GD(STI)-77
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Measure reaction time (t1, t2, t3) and reaction time (t4, t5, t6). Use the average value of the reaction time to
obtain the diagnostic value.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 1000 ms × [1 time(s)/2] + 1000 ms × 3 time(s) + 500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
BF:DTC P015B O2 SENSOR DELAYED RESPONSE - LEAN TO RICH (BANK 1
SENSOR 1)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P015A. <Ref. to GD(STI)-73, DTC P015A O2 SENSOR DELAYED
RESPONSE - RICH TO LEAN (BANK 1 SENSOR 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
Judgment Value
Malfunction Criteria Threshold Value DTC
(t1 + t2 + t3)/3 > 380 ms P015A and P015B
and
(t4 + t5 + t6)/3 > 380 ms
EN-09891
Time
Lean
Rich
Lean
Rich
STFT
Time
Sensor output
t1 t2 t3
t4 t5 t6
15WRX_STI_US_EN.book 77 ペー   
GD(STI)-78
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BG:DTC P0171 SYSTEM TOO LEAN (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect fuel system malfunction by the amount of main feedback control.
Fuel system is diagnosed by comparing the target air fuel ratio calculated by ECM with the actual air fuel ratio
measured by sensor.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously at idling or at a constant speed after warming up the engine.
4. DIAGNOSTIC METHOD
Compare the diagnostic value (fsobd) with the threshold value, and if a condition meeting the malfunction cri-
teria below continues for 10 s × 3 time(s) or more, judge that there is a fault in the fuel system.
Time Needed for Diagnosis: 10 s × 3 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
A/F main learning system In operation
Judgment Value
Malfunction Criteria Threshold Value
fsobd = (sglmd – tglmda) + faf + flaf Value from Map
In this case: sglmd = measured lambda
tglmda = target lambda
faf = main feedback compensation coefficient (every 64 milliseconds)
flaf = main feedback learning compensation coefficient
Map
Amount of air (g (oz)/s) 0 (0)
2.34375
(0.08)
4.6875
(0.17)
7.03125
(0.25)
9.375
(0.33)
11.71875
(0.41)
14.0625
(0.5)
fsobdL1 (%) 1.35 1.35 1.35 1.35 1.35 1.35 1.35
15WRX_STI_US_EN.book 78 ペー   
GD(STI)-79
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BH:DTC P0172 SYSTEM TOO RICH (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect fuel system malfunction by the amount of main feedback control.
Fuel system is diagnosed by comparing the target air fuel ratio calculated by ECM with the actual air fuel ratio
measured by sensor.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously at idling or at a constant speed after warming up the engine.
4. DIAGNOSTIC METHOD
Compare the diagnostic value (fsobd) with the threshold value, and if a condition meeting the malfunction cri-
teria below continues for 10 s × 3 time(s) or more, judge that there is a fault in the fuel system.
Time Needed for Diagnosis: 10 s × 3 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
A/F main learning system In operation
Judgment Value
Malfunction Criteria Threshold Value
fsobd = (sglmd – tglmda) + faf + flaf < Value from Map
In this case: sglmd = measured lambda
tglmda = target lambda
faf = main feedback compensation coefficient (every 64 milliseconds)
flaf = main feedback learning compensation coefficient
Map
Warm-up increase compensation coefficient 0 0.102 0.199 0.301
Threshold Value 0.65 – 0 0.65 – 0.103 0.65 – 0.174 0.65 – 0.236
Warm-up increase compensation coefficient 0.330 0.500 0.602
Threshold Value 0.65 – 0.249 0.65 – 0.249 0.65 – 0.249
15WRX_STI_US_EN.book 79 ペー   
GD(STI)-80
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BI: DTC P0201 INJECTOR #1
1. OUTLINE OF DIAGNOSIS
Based on the self-diagnostic result of the injector driving IC, judge the injector driving circuit as normal or ab-
normal.
Injector driving IC detects the status of “fuel remains injected” or “fuel is not injected” as a malfunction.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 10 time(s) × 256/1000 s
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
BJ:DTC P0202 INJECTOR #2
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0201. <Ref. to GD(STI)-80, DTC P0201 INJECTOR #1, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
BK:DTC P0203 INJECTOR #3
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0201. <Ref. to GD(STI)-80, DTC P0201 INJECTOR #1, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
BL:DTC P0204 INJECTOR #4
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0201. <Ref. to GD(STI)-80, DTC P0201 INJECTOR #1, Diagnostic
Trouble Code (DTC) Detecting Criteria.>
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine > 1 s
Engine speed > 500 rpm
Injection status Not during fuel cut
Judgment Value
Malfunction Criteria Threshold Value
Injector driving IC information Malfunction
15WRX_STI_US_EN.book 80 ペー   
GD(STI)-81
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BM:DTC P0222 THROTTLE/PEDAL POSITION SENSOR/SWITCH “B” CIRCUIT
LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of throttle position sensor 2.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 24 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Throttle position sensor 1 signal (3) Throttle position sensor (4) Engine control module (ECM)
(2) Throttle position sensor 2 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 2 input voltage 1.15 V
EN-01859
(1)
(2)
(3)
(4)
15WRX_STI_US_EN.book 81 ペー   
GD(STI)-82
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BN:DTC P0223 THROTTLE/PEDAL POSITION SENSOR/SWITCH “B” CIRCUIT
HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of throttle position sensor 2.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 24 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Throttle position sensor 1 signal (3) Throttle position sensor (4) Engine control module (ECM)
(2) Throttle position sensor 2 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 2 input voltage 4.858 V
EN-01859
(1)
(2)
(3)
(4)
15WRX_STI_US_EN.book 82 ペー   
GD(STI)-83
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BO:DTC P0230 FUEL PUMP PRIMARY CIRCUIT
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of fuel pump control unit.
Judge as NG when the NG signal is sent through a diagnostic line coming from the fuel pump control unit.
Fuel pump control unit detects the open or short circuit malfunction for each line, and then sends NG signals
if one of them is found NG.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) Engine control module (ECM) (3) Fuel pump (4) Battery
(2) Fuel pump control unit
Secondary Parameters Enable Conditions
Battery voltage 8 V
Fuel level 9 2 (2.38 US gal, 1.98 Imp gal)
Elapsed time after starting the engine 180000 ms
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.35 V
EN-01771
E
E
(3)
(4)
(2)
FPC
DI
FP+
FP-
+B
(1)
15WRX_STI_US_EN.book 83 ペー   
GD(STI)-84
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BP:DTC P0244 TURBO/SUPER CHARGER WASTEGATE SOLENOID “A”
RANGE/PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of wastegate control solenoid valve function.
Judge as NG when becoming high wastegate pressure.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Coil
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Intake manifold pressure > Value from Map
Map
Barometric pressure (kPa (mmHg, inHg))
59.3 (445, 17.5) 68.7 (515, 20.3) 78 (585, 23) 92 (690, 27.2) 96 (720, 28.3) 98.7 (740, 29.1)
Engine
speed
(rpm)
1000 124.5 (934, 36.8) 135.3 (1015, 40) 135.3 (1015, 40) 135.3 (1015, 40) 135.3 (1015, 40) 135.3 (1015 , 40)
2000 169.5 (1271, 50) 185.3 (1390, 54.7) 185.3 (1390, 54.7) 185.3 (1390, 54.7) 185.3 (1390, 54.7)
185.3 (1390 , 54.7)
3000 158.3 (1187, 46.7) 214.6 (1610, 63.4) 214.6 (1610, 63.4) 214.6 (1610, 63.4) 214.6 (1610, 63.4)
214.6 (1610 , 63.4)
4000 155.8 (1169, 46) 195.5 (1467, 57.7) 205.4 (1541, 60.7) 225.3 (1690, 66.5) 225.3 (1690, 66.5)
225.3 (1690 , 66.5)
5000 145.9 (1094, 43.1) 169.7 (1273, 50.1) 185.6 (1392, 54.8) 215.4 (1616, 63.6) 225.3 (1690, 66.5)
225.3 (1690 , 66.5)
6000 117.9 (884, 34.8) 156.4 (1173, 46.2) 168.5 (1264, 49.8) 205 (1538, 60.5) 215.1 (1614, 63.5)
229.3 (1720 , 67.7)
kPa (mmHg, inHg)
EN-01772
(1)
15WRX_STI_US_EN.book 84 ペー   
GD(STI)-85
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BQ:DTC P0245 TURBO/SUPER CHARGER WASTEGATE SOLENOID “A” LOW
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the wastegate control solenoid valve.
Judge as NG when the terminal output voltage remains Low during outputting the duty signal.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after starting the engine.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 640 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Coil
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 1 s
Duty ratio of wastegate control < 75%
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.34 V
EN-01772
(1)
15WRX_STI_US_EN.book 85 ペー   
GD(STI)-86
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BR:DTC P0246 TURBO/SUPER CHARGER WASTEGATE SOLENOID “A” HIGH
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the wastegate control solenoid valve.
Judge as NG when the terminal output voltage remains Low or High during outputting the duty signal.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after starting the engine.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 640 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
BS:DTC P0300 RANDOM/MULTIPLE CYLINDER MISFIRE DETECTED
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0301. <Ref. to GD(STI)-87, DTC P0301 CYLINDER 1 MISFIRE
DETECTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>
(1) Coil
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 1 s
Duty ratio of wastegate control 25%
Judgment Value
Malfunction Criteria Threshold Value
Output current 12 A
EN-01772
(1)
15WRX_STI_US_EN.book 86 ペー   
GD(STI)-87
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BT:DTC P0301 CYLINDER 1 MISFIRE DETECTED
1. OUTLINE OF DIAGNOSIS
Detect the presence of misfire occurrence. (Revolution fluctuation method)
Monitoring Misfire which influences exhaust deterioration (1.5 times of FTP) and catalyst damage is made
obligatory by the law. Misfire affecting these two has two patterns below:
Intermittent misfire (The same cylinder misfires in random, or different cylinders misfire in random.): FTP
1.5 times misfire
Every time misfire (The same cylinder misfires every time.): FTP 1.5 times misfire, Catalyst damage mis-
fire
The following detecting methods are adopted for these detection.
1) Intermittent misfire: FTP 1.5 times misfire
180° Interval Difference Method
360° Interval Difference Method (whole range)
720° Interval Difference Method (3,000 rpm or more)
2) Misfire every time: FTP 1.5 times misfire, Catalyst damage misfire
360° Interval Difference Method
15WRX_STI_US_EN.book 87 ペー   
GD(STI)-88
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
2. ENABLE CONDITIONS
Map
Normal ignition
Secondary Parameters Enable Conditions
Battery voltage 8 V
Fuel level 9 2 (2.38 US gal, 1.98 Imp gal)
Throttle position change during 16 milliseconds < 14 °
Fuel shut-off function Not in operation
Vehicle dynamic control or AT torque control Not in operation
Second diagnosis of P0441 Not in operation
Engine speed 550 rpm — 6800 rpm
Intake manifold pressure > Value from Map
Barometric pressure (kPa (mmHg, inHg))
66.7
(500, 19.7)
76.7
(575, 22.6)
80
(600, 23.6)
84
(630, 24.8)
86.7
(650, 25.6)
92
(690, 27.2)
100.3
(752, 29.6)
Engine
speed
(rpm)
700
26.7
(200.0 , 7.9)
26.7
(200.0 , 7.9)
27.3
(205.0 , 8.1)
28.4
(213.0 , 8.4)
29.3
(220.0 , 8.7)
29.9
(224.0 , 8.8)
28.8
(216.0 , 8.5)
1000
23.9
(179.0 , 7)
23.9
(179.0 , 7)
24.9
(187.0 , 7.4)
25.5
(191.0 , 7.5)
25.9
(194.0 , 7.6)
27.5
(206.0 , 8.1)
28.6
(214.7 , 8.5)
1500
22.4
(168.0 , 6.6)
22.4
(168.0 , 6.6)
23.3
(175.0 , 6.9)
24.1
(181.0 , 7.1)
24.7
(185.0 , 7.3)
24.8
(186.0 , 7.3)
24.9
(186.9 , 7.4)
2000
23.2
(174.0 , 6.9)
23.2
(174.0 , 6.9)
24
(180.0 , 7.1)
25.5
(191.0 , 7.5)
26.1
(196.0 , 7.7)
25.6
(192.0 , 7.6)
25.3
(189.5 , 7.5)
2500
23.9
(179.0 , 7)
23.9
(179.0 , 7)
24.5
(184.0 , 7.2)
25.5
(191.0 , 7.5)
26
(195.0 , 7.7)
25.5
(191.0 , 7.5)
25.1
(188.6 , 7.4)
3000
24.7
(185.0 , 7.3)
24.7
(185.0 , 7.3)
25.3
(190.0 , 7.5)
25.6
(192.0 , 7.6)
26.1
(196.0 , 7.7)
25.9
(194.0 , 7.6)
25.8
(193.3 , 7.6)
3500
29.1
(218.5 , 8.6)
29.1
(218.5 , 8.6)
29.8
(223.5 , 8.8)
29.9
(224.5 , 8.8)
31.3
(234.5 , 9.2)
31.5
(236.0 , 9.3)
29.5
(221.5 , 8.7)
4000
29.2
(219.0 , 8.6)
29.2
(219.0 , 8.6)
29.9
(224.0 , 8.8)
30.5
(229.0 , 9)
30.8
(231.0 , 9.1)
31.7
(238.0 , 9.4)
32.3
(242.2 , 9.5)
4500
29.3
(219.5 , 8.6)
29.3
(219.5 , 8.6)
30.3
(227.5 , 9)
30.9
(231.5 , 9.1)
31.4
(235.5 , 9.3)
32.1
(241.0 , 9.5)
32.6
(244.2 , 9.6)
5000
30.4
(228.1 , 9)
30.4
(228.1 , 9)
30.7
(230.1 , 9.1)
31.7
(238.1 , 9.4)
32.1
(241.1 , 9.5)
32.7
(245.0 , 9.6)
33.1
(248.0 , 9.8)
5500
33.4
(250.6 , 9.9)
33.4
(250.6 , 9.9)
34.2
(256.6 , 10.1)
34.9
(261.6 , 10.3)
35.1
(263.6 , 10.4)
35.7
(268.0 , 10.6)
36.1
(271.0 , 10.7)
6000
37.5
(281.1 , 11.1)
37.5
(281.1 , 11.1)
38
(285.1 , 11.2)
38.8
(291.1 , 11.5)
39.1
(293.1 , 11.5)
40.3
(302.0 , 11.9)
40.9
(306.9 , 12.1)
6500
42.6
(319.6 , 12.6)
42.6
(319.6 , 12.6)
43.3
(324.6 , 12.8)
43.9
(329.6 , 13)
43.8
(328.6 , 12.9)
44.9
(337.0 , 13.3)
45.6
(341.7 , 13.5)
6700
43.3
(325, 12.8)
43.3
(325, 12.8)
44
(330, 13)
44.7
(335, 13.2)
44.5
(334, 13.1)
45.6
(342, 13.5)
46.3
(347.1442749, 13.7)
kPa (mmHg, inHg)
15WRX_STI_US_EN.book 88 ペー   
GD(STI)-89
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Idling ignition
3. GENERAL DRIVING CYCLE
If conditions are met, it is possible to detect the misfires from idling to high engine speed. However, in case
any engine load or breakage occurs, perform with the engine at idle.
Perform the diagnosis continuously.
Barometric pressure (kPa (mmHg, inHg))
66.7
(500, 19.7)
76.7
(575 , 22.6)
80
(600 , 23.6)
84
(630 , 24.8)
86.7
(650 , 25.6)
92
(690 , 27.2)
100.3
(752 , 29.6)
Engine
speed
(rpm)
700
26.7
(200.0 , 7.9)
26.7
(200.0 , 7.9)
27.3
(205.0 , 8.1)
28.4
(213.0 , 8.4)
29.3
(220.0 , 8.7)
29.9
(224.0 , 8.8)
28.8
(216.0 , 8.5)
1000
25.1
(188.0 , 7.4)
25.1
(188.0 , 7.4)
26
(195.0 , 7.7)
26.9
(202.0 , 8)
28
(210.0 , 8.3)
28.7
(215.0 , 8.5)
30.4
(228.1 , 9)
1500
22.9
(172.0 , 6.8)
22.9
(172.0 , 6.8)
23.3
(175.0 , 6.9)
23.9
(179.0 , 7)
24.7
(185.0 , 7.3)
24.9
(187.0 , 7.4)
26.7
(200.6 , 7.9)
2000
23.2
(174.0 , 6.9)
23.2
(174.0 , 6.9)
23.7
(178.0 , 7)
24.4
(183.0 , 7.2)
25.1
(188.0 , 7.4)
25.3
(190.0 , 7.5)
27.8
(208.5 , 8.2)
2500
23.2
(174.0 , 6.9)
23.2
(174.0 , 6.9)
23.7
(178.0 , 7)
24.5
(184.0 , 7.2)
24.8
(186.0 , 7.3)
25.3
(190.0 , 7.5)
26.6
(199.7 , 7.9)
3000
24.3
(182.0 , 7.2)
24.3
(182.0 , 7.2)
24.9
(187.0 , 7.4)
25.9
(194.0 , 7.6)
25.9
(194.0 , 7.6)
26.1
(196.0 , 7.7)
26.6
(199.7 , 7.9)
3500
31.7
(237.5 , 9.4)
31.7
(237.5 , 9.4)
31.4
(235.5 , 9.3)
32.6
(244.5 , 9.6)
33.1
(248.5 , 9.8)
34.6
(259.5 , 10.2)
35.2
(264.0 , 10.4)
4000
32.1
(241.0 , 9.5)
32.1
(241.0 , 9.5)
32.3
(242.0 , 9.5)
33.2
(249.0 , 9.8)
33.7
(253.0 , 10)
34.9
(262.0 , 10.3)
36
(270.0 , 10.6)
4500
32.1
(240.5 , 9.5)
32.1
(240.5 , 9.5)
32.1
(240.5 , 9.5)
33
(247.5 , 9.7)
33.9
(254.5 , 10)
35.5
(266.5 , 10.5)
35.3
(265.1 , 10.4)
5000
35.5
(266.1 , 10.5)
35.5
(266.1 , 10.5)
34.4
(258.1 , 10.2)
35.3
(265.1 , 10.4)
35.7
(268.1 , 10.6)
37.3
(280.1 , 11)
37.2
(279.2 , 11)
5500
38.1
(285.6 , 11.2)
38.1
(285.6 , 11.2)
37.5
(281.6 , 11.1)
38.5
(288.6 , 11.4)
39.5
(296.6 , 11.7)
40.3
(302.6 , 11.9)
40.7
(305.2 , 12)
6000
41.6
(312.1 , 12.3)
41.6
(312.1 , 12.3)
41.5
(311.1 , 12.2)
42.8
(321.1 , 12.6)
43.5
(326.1 , 12.8)
45.6
(342.1 , 13.5)
45.4
(340.3 , 13.4)
6500
48.6
(364.6 , 14.4)
48.6
(364.6 , 14.4)
49.3
(369.6 , 14.6)
48.6
(364.6 , 14.4)
49.4
(370.6 , 14.6)
49.4
(370.6 , 14.6)
53.4
(400.7 , 15.8)
6700
49.3
(370, 14.6)
49.3
(370, 14.6)
50
(375, 14.8)
49.3
(370, 14.6)
50.1
(376, 14.8)
50.1
(376, 14.8)
54.1
(406.1514536, 16)
kPa (mmHg, inHg)
15WRX_STI_US_EN.book 89 ペー   
GD(STI)-90
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
4. DIAGNOSTIC METHOD
When a misfire occurs, the engine speed will decrease and the crankshaft position speed will change. Cal-
culate the interval difference value (diagnostic value) from crankshaft position speed by the following formu-
la, and judge whether a misfire is occurring or not comparing the calculated result with judgment value. Count
the number of misfires, if the misfire ratio is higher during 1000 revs. or 200 revs., judge corresponding cyl-
inders as NG.
As shown in the following figure, pick a cylinder as the standard and name it omg 0. And the former crank-
shaft position speed is named omg 1, the second former crankshaft position speed is named omg 2, the third
is named omg 3, etc.
Diagnostic value calculation
(Calculate from angle speed)
Misfire detection every single ignition
(Compare diagnostic value with judg-
ment value)
NG judgment (Misfire occurrence judgment required
by the law) (Compare number of misfire with judg-
ment value)
180° Interval Difference Method
360° Interval Difference Method
720° Interval Difference Method
FTP 1.5 times misfire NG judgment
Catalyst damage misfire NG judgment
(A) Ignition order (B) Crankshaft position speed
EN-01774
#3 #2 #4 #1 #3 #2 #4 #1 #3 #2(A)
(B)
omg0omg1omg2omg3omg4omg5omg6 omg7
15WRX_STI_US_EN.book 90 ペー   
GD(STI)-91
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
180° Interval Difference Method
360° Interval Difference Method
Diagnostic value domg 180 = (omg 1 – omg 0) – (omg 5 – omg 1)/4
Judge as a misfire in the following cases.
domg 180 > judgment value of positive side
domg 180 judgment value of negative side
(Diagnostic value before 180° CA)
Diagnostic value domg 360 = (omg 1 – omg 0) – (omg 3 – omg 2)
Misfire judgment domg 360 > Judgment value Judge as misfire
Judged as misfire.
Threshold value (positive number)
Threshold value (negative number)
domg180
domg180
EN-02877
Judged as misfire.
Threshold value
domg360
domg360
EN-03273
15WRX_STI_US_EN.book 91 ペー   
GD(STI)-92
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
720° Interval Difference Method
FTP 1.5 times misfire (Misfire occurrence level which influences exhaust gas)
Time Needed for Diagnosis: 1000 engine revs.
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Diagnostic value domg 720 = (omg 1 – omg 0) – (omg 5 – omg 4)
Misfire judgment domg 720 > Judgment value Judge as misfire
Judgment Value (Judge that malfunction occurs when the misfire ratio is high in 1000 engine revs.)
Malfunction Criteria Threshold Value
FTP emission diagnostic value 16 × 100/2000% in 1000 revs.
Judged as misfire.
Threshold value
domg720
domg720
EN-03274
15WRX_STI_US_EN.book 92 ペー   
GD(STI)-93
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Catalyst damage misfire (Misfire occurrence level damaging catalyst)
Map 3
Time Needed for Diagnosis: 200 engine revs.
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Judgment Value
Malfunction Criteria Threshold Value
Catalyst damage misfire diagnostic value Value from Map 3
Intake air (g(oz)/rev)
0.2 (0.01) 0.4 (0.01) 0.6 (0.02) 0.8 (0.03) 1 (0.04) 1.2 (0.04) 1.4 (0.05) 1.6 (0.06) 1.8 (0.06) 2 (0.07)
Engine
speed
(rpm)
700 148 128 116 106 100 90 90 90 90 90
1000 148 128 114 104 92 85 85 85 85 85
1500 140 118 102 90 85 85 85 72 72 72
2000 128 90 90 73 58 43 40 36 32 20
2500 116 87 57 45 39 36 34 32 30 20
3000 108 87 58 39 36 36 32 30 28 20
350074744327232220202020
400061614027222020202020
450055553425202020202020
500055553423202020202020
550054543322202020202020
600052523221202020202020
650050503020202020202020
670050503020202020202020
15WRX_STI_US_EN.book 93 ペー   
GD(STI)-94
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BU:DTC P0302 CYLINDER 2 MISFIRE DETECTED
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0301. <Ref. to GD(STI)-87, DTC P0301 CYLINDER 1 MISFIRE
DETECTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>
BV:DTC P0303 CYLINDER 3 MISFIRE DETECTED
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0301. <Ref. to GD(STI)-87, DTC P0301 CYLINDER 1 MISFIRE
DETECTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>
BW:DTC P0304 CYLINDER 4 MISFIRE DETECTED
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0301. <Ref. to GD(STI)-87, DTC P0301 CYLINDER 1 MISFIRE
DETECTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>
15WRX_STI_US_EN.book 94 ペー   
GD(STI)-95
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BX:DTC P0327 KNOCK SENSOR 1 CIRCUIT LOW (BANK 1 OR SINGLE SEN-
SOR)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of knock sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) To knock sensor harness
(1) Case (3) Piezoelectric element (5) Resistance
(2) Weight (4) Nut
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.243 V
EN-01707
(1)
(2)
(3)
(4)
(5)
(A)
15WRX_STI_US_EN.book 95 ペー   
GD(STI)-96
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BY:DTC P0328 KNOCK SENSOR 1 CIRCUIT HIGH (BANK 1 OR SINGLE SEN-
SOR)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of knock sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(A) To knock sensor harness
(1) Case (3) Piezoelectric element (5) Resistance
(2) Weight (4) Nut
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.709 V
EN-01707
(1)
(2)
(3)
(4)
(5)
(A)
15WRX_STI_US_EN.book 96 ペー   
GD(STI)-97
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BZ:DTC P0335 CRANKSHAFT POSITION SENSOR “A” CIRCUIT
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the crankshaft position sensor.
Judge as NG when the crank signal is not input even though the starter was rotated.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
(A) Camshaft signal (RH) (B) Camshaft signal (LH) (C) Crankshaft signal
(1) Crankshaft position sensor (2) Crank sprocket (3) Crankshaft half-turn
Secondary Parameters Enable Conditions
Battery voltage 8 V
EN-06283
(A)
(C)
10
30
30
(B)
#1BTDC10 CA
#3BTDC10 CA #2BTDC10 CA #4BTDC10 CA #1BTDC10 CA
50 CA 50 CA
50 CA
50 CA
50 CA50 CA
(1)
(2)
(3)
EN-05539
15WRX_STI_US_EN.book 97 ペー   
GD(STI)-98
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 3000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Judgment Value
Malfunction Criteria Threshold Value
Number of crankshaft position sensor signals during cranking = 0
15WRX_STI_US_EN.book 98 ペー   
GD(STI)-99
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CA:DTC P0336 CRANKSHAFT POSITION SENSOR “A” CIRCUIT RANGE/PER-
FORMANCE
1. OUTLINE OF DIAGNOSIS
Detect for faults in crankshaft position sensor output properties.
Judge as NG when there is a problem in the number of crankshaft signals for every revolution.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
(A) Camshaft signal (RH) (B) Camshaft signal (LH) (C) Crankshaft signal
(D) Normal: Number of crankshaft sig-
nals = 30
(1) Crankshaft position sensor (2) Crank sprocket (3) Crankshaft half-turn
Secondary Parameters Enable Conditions
Battery voltage 8 V
EN-06384
(A)
(C)
10
30
30
(B)
#1BTDC10 CA
#3BTDC10 CA #2BTDC10 CA #4BTDC10 CA #1BTDC10 CA
50 CA 50 CA
50 CA
50 CA
50 CA50 CA
(D)
(1)
(2)
(3)
EN-05539
15WRX_STI_US_EN.book 99 ペー   
GD(STI)-100
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 10 engine revs.
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Amount of crank sensor signal during 1 rev. 30
15WRX_STI_US_EN.book 100 ージ 20  
GD(STI)-101
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CB:DTC P0340 CAMSHAFT POSITION SENSOR “A” CIRCUIT (BANK 1 OR SIN-
GLE SENSOR)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the camshaft position sensor.
When there is no camshaft position signal input continuously, judge as NG.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Diagnosis 1: Perform the diagnosis only once.
Diagnosis 2: Always perform the diagnosis continuously.
(A) Camshaft signal (RH) (B) Camshaft signal (LH) (C) Crankshaft signal
(D) Camshaft position signal: When
normal, there will be 3 camshaft
position signals for every 2 crank-
shaft revolutions.
Diagnosis 1
Secondary Parameters Enable Conditions
Battery voltage 8 V
Diagnosis 2
Secondary Parameters Enable Conditions
Battery voltage 8 V
Elapsed time after starting the engine 200 ms
EN-06382
(A)
(C)
10
30
30
(B)
#1BTDC10 CA
#3BTDC10 CA #2BTDC10 CA #4BTDC10 CA #1BTDC10 CA
50 CA 50 CA
50 CA
50 CA
50 CA50 CA
(D)
15WRX_STI_US_EN.book 101 ージ 20  
GD(STI)-102
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Diagnosis 1
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 3000 ms
Diagnosis 2
Judge as NG when no input status of camshaft position sensor signal continues for (10 time(s) +2)/2 revs.
Time Needed for Diagnosis: (10 time(s) +2)/2 engine revs.
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Judgment Value
Malfunction Criteria Threshold Value
Number of camshaft position sensor signals during cranking = 0
Judgment Value
Malfunction Criteria Threshold Value
Amount of camshaft sensor signal during 0.5 revs of crankshaft = 0
15WRX_STI_US_EN.book 102 ージ 20  
GD(STI)-103
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CC:DTC P0341 CAMSHAFT POSITION SENSOR "A" CIRCUIT RANGE/PERFOR-
MANCE (BANK 1 OR SINGLE SENSOR)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of camshaft position sensor property.
Judge as NG when the number of camshaft signals remains abnormal.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
(A) Camshaft signal (RH) (B) Camshaft signal (LH) (C) Crankshaft signal
(D) Camshaft position signal: When
normal, there will be 3 camshaft
position signals for every 2 crank-
shaft revolutions.
Diagnosis 1
Secondary Parameters Enable Conditions
Battery voltage 8 V
Elapsed time after starting the engine 200 ms
Diagnosis 2
Secondary Parameters Enable Conditions
Battery voltage 8 V
Elapsed time after starting the engine 200 ms
Engine speed < 5000 rpm
Diagnosis 3
Secondary Parameters Enable Conditions
Battery voltage 8 V
Elapsed time after starting the engine 200 ms
Engine speed 5000 rpm
EN-06382
(A)
(C)
10
30
30
(B)
#1BTDC10 CA
#3BTDC10 CA #2BTDC10 CA #4BTDC10 CA #1BTDC10 CA
50 CA 50 CA
50 CA
50 CA
50 CA50 CA
(D)
15WRX_STI_US_EN.book 103 ージ 20  
GD(STI)-104
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Diagnosis 1: Judge as NG when the number of camshaft position sensor signals in two crankshaft revolu-
tions is less than 3 time(s).
Diagnosis 2: Judge as NG when the number of camshaft position sensor signals in two crankshaft revolu-
tions is more than 3 time(s).
Diagnosis 3: Judge as NG when the number of camshaft position sensor signals in two crankshaft revolu-
tions is more than 12 time(s).
Time Needed for Diagnosis: Two engine revs. × 4 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
CD:DTC P0345 CAMSHAFT POSITION SENSOR “A” CIRCUIT (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0340. <Ref. to GD(STI)-101, DTC P0340 CAMSHAFT POSITION
SENSOR “A” CIRCUIT (BANK 1 OR SINGLE SENSOR), Diagnostic Trouble Code (DTC) Detecting Crite-
ria.>
CE:DTC P0346 CAMSHAFT POSITION SENSOR "A" CIRCUIT RANGE/PERFOR-
MANCE (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0341. <Ref. to GD(STI)-103, DTC P0341 CAMSHAFT POSITION
SENSOR "A" CIRCUIT RANGE/PERFORMANCE (BANK 1 OR SINGLE SENSOR), Diagnostic Trouble
Code (DTC) Detecting Criteria.>
Judgment Value
Malfunction Criteria Threshold Value
Amount of camshaft sensor signal during 2 revs of crankshaft < 3 time(s)
Judgment Value
Malfunction Criteria Threshold Value
Amount of camshaft sensor signal during 2 revs of crankshaft > 3 time(s)
Judgment Value
Malfunction Criteria Threshold Value
Amount of camshaft sensor signal during 2 revs of crankshaft > 12 time(s)
15WRX_STI_US_EN.book 104 ージ 20  
GD(STI)-105
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CF:DTC P0351 IGNITION COIL A PRIMARY/SECONDARY CIRCUIT
1. OUTLINE OF DIAGNOSIS
Based on the self-diagnostic result of the ignition coil driving IC, judge the ignition coil driving circuit as normal
or abnormal.
The ignition coil driving IC detects “no ignition” status as a malfunction.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 10 time(s) × 256/1000 s
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
CG:DTC P0352 IGNITION COIL B PRIMARY/SECONDARY CIRCUIT
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0351. <Ref. to GD(STI)-105, DTC P0351 IGNITION COIL A PRI-
MARY/SECONDARY CIRCUIT, Diagnostic Trouble Code (DTC) Detecting Criteria.>
CH:DTC P0353 IGNITION COIL C PRIMARY/SECONDARY CIRCUIT
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0351. <Ref. to GD(STI)-105, DTC P0351 IGNITION COIL A PRI-
MARY/SECONDARY CIRCUIT, Diagnostic Trouble Code (DTC) Detecting Criteria.>
CI: DTC P0354 IGNITION COIL D PRIMARY/SECONDARY CIRCUIT
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0351. <Ref. to GD(STI)-105, DTC P0351 IGNITION COIL A PRI-
MARY/SECONDARY CIRCUIT, Diagnostic Trouble Code (DTC) Detecting Criteria.>
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine > 1 s
Engine speed > 500 rpm
Judgment Value
Malfunction Criteria Threshold Value
Ignition driving IC information Malfunction
15WRX_STI_US_EN.book 105 ージ 20  
GD(STI)-106
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CJ:DTC P0365 CAMSHAFT POSITION SENSOR “B” CIRCUIT (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the camshaft position sensor.
When there is no camshaft position signal input continuously, judge as NG.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
Judge as NG when no input status of camshaft position sensor signal continues for (10 time(s) +2)/2 revs.
Time Needed for Diagnosis: (10 time(s) +2)/2 engine revs.
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 200 ms
Judgment Value
Malfunction Criteria Threshold Value
Amount of camshaft sensor signal during 0.5 revs of crankshaft = 0
15WRX_STI_US_EN.book 106 ージ 20  
GD(STI)-107
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CK:DTC P0366 CAMSHAFT POSITION SENSOR B CIRCUIT RANGE/PERFOR-
MANCE (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of camshaft position sensor property.
Judge as NG when the number of camshaft signals remains abnormal.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
Judge as NG when the status continues where the number of camshaft position sensor signals in two crank-
shaft revolutions is other than 2 time(s).
Time Needed for Diagnosis: Two engine revs. × 4 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
CL:DTC P0390 CAMSHAFT POSITION SENSOR “B” CIRCUIT (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0365. <Ref. to GD(STI)-106, DTC P0365 CAMSHAFT POSITION
SENSOR “B” CIRCUIT (BANK 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CM:DTC P0391 CAMSHAFT POSITION SENSOR B CIRCUIT RANGE/PERFOR-
MANCE (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0366. <Ref. to GD(STI)-107, DTC P0366 CAMSHAFT POSITION
SENSOR B CIRCUIT RANGE/PERFORMANCE (BANK 1), Diagnostic Trouble Code (DTC) Detecting Cri-
teria.>
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 200 ms
Judgment Value
Malfunction Criteria Threshold Value
Amount of camshaft sensor signal during 2 revs of crankshaft 2 time(s)
15WRX_STI_US_EN.book 107 ージ 20  
GD(STI)-108
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CN:DTC P0410 SECONDARY AIR INJECTION SYSTEM
1. OUTLINE OF DIAGNOSIS
Detect NG judging from secondary air delivery pipe pressure, pulse of secondary air delivery pipe pressure
and secondary air pipe airflow amount.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform diagnosis during secondary air pump operation
Secondary Parameters Enable Conditions
Pump supply pressure check
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Estimate ambient temperature 4.4 °C
Secondary air pump Operating
Combination valve both closed pulse diagnosis
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Estimate ambient temperature 4.4 °C
Secondary air pump Operating
Engine load 0.2 g/rev (0.01 oz/rev)
Elapsed time after fuel cut 1000 ms
Combination valve changeover pressure diagnosis
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Estimate ambient temperature 4.4 °C
Secondary air pump Operating
Amount of intake air < 25 g/s (0.88 oz/s)
Elapsed time after fuel cut 1000 ms
Overflow diagnosis
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Estimate ambient temperature 4.4 °C
Secondary air pump Operating
Amount of intake air < 25 g/s (0.88 oz/s)
Elapsed time after fuel cut 1000 ms
15WRX_STI_US_EN.book 108 ージ 20  
GD(STI)-109
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
4. DIAGNOSTIC METHOD
Measure secondary air delivery pipe pressure, pulse of secondary air delivery pipe pressure and secondary
air pipe airflow amount.
(1) Ignition switch (6) Secondary air delivery pipe pres-
sure (psi)
(10) Barometric pressure (Pas) mea-
surement before secondary air
control
(2) Engine speed (7) Diagnosis enable condition (11) Right bank all closed pressure
(P0R) measurement
(3) Secondary air pump operating
status
(8) Pump supply pressure check
(judgment)
(12) Both banks all closed pressure
(P0RL) measurement
(4) E-COMB valve (right hand) status (9) Flow amount check (judgment) (13) Left bank all closed pressure
(P0L) measurement
(5) E-COMB valve (left hand) status
(2)
(7)
(8)
(6)
(12)
(11)
(10)
(13)
(9)
EN-05591
(3)
ON
OFF
(1)
ON
OFF
(4)
OPEN
CLOSE
(5)
OPEN
CLOSE
15WRX_STI_US_EN.book 109 ージ 20  
GD(STI)-110
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Pump supply pressure check
Perform the system function diagnosis with how much the pressure rises when the secondary air pump is
turned from OFF to ON.
Judge as NG if delivery pipe pressure does not rise though it should when the secondary air pump turns OFF
ON.
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 4000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Combination valve both closed pulse diagnosis
Perform open stuck diagnosis of both combination valves using delivery pipe pressure pulse when both com-
bination valves are closed. Determine which side of valves is stuck open by comparing secondary air flow
amount when RH combination valve is closed with that when LH combination valve is closed.
Calculate voltage pulse of the pump delivery pipe pressure when both combination valves are closed. The
calculation should be small because there is no pulse from supply pipe pressure with both combination
valves closed. When the calculation is large, determine that either of the combination valves is stuck open.
Determine which side of valves is stuck open by comparing secondary air flow amount when the RH combi-
nation valve is closed with that when the LH combination valve is closed. Air flow amount is larger on the
open stuck valve.
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 992 ms + 992 ms + 992 ms + 4000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value DTC
Secondary air supply pipe pressure (after barometric pressure compensation) < 0.9 kPa (7 mmHg, 0.3 inHg) P0410
Judgment Value
Malfunction Criteria Threshold Value DTC
Pulse calculation value when both combination valves are closed > Value of Map 3 P2440
Air flow amount when the right bank is closed (value from Map 4) Air flow amount when the left bank is closed
(value from Map 5)
Pulse calculation value when both combination valves are closed > Value of Map 3 P2442
Air flow amount when the left bank is closed (value from Map 5) > Air flow amount when the right bank is closed
(value from Map 4)
15WRX_STI_US_EN.book 110 ージ 20  
GD(STI)-111
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Combination valve changeover pressure diagnosis
Perform the RH combination valve stuck closed diagnosis with the variation of delivery pipe pressure when
the RH combination valve turns closed open.
Delivery pipe pressure should vary when the RH combination valve turns closed open. When the variation
is small, determine that the RH combination valve is stuck closed.
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 992 ms + 992 ms + 992 ms + 4000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Perform the LH combination valve stuck closed diagnosis with the variation of delivery pipe pressure when
the LH combination valve turns open closed.
Delivery pipe pressure should vary when the LH combination valve turns open closed. When the variation
is small, determine that the LH combination valve is stuck closed.
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 992 ms + 992 ms + 992 ms + 4000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Overflow diagnosis
Perform secondary air system flow abnormality diagnosis using both sides of combination valves secondary
air amount when both are closed.
Judge as secondary air system flow abnormality either if there is excessive secondary air flow amount with
the RH combination valve closed, or if there is excessive secondary air flow amount with the LH combination
valve closed.
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 992 ms + 992 ms + 992 ms + 4000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value DTC
Pressure variation value when the RH combination valve
is switched
< Value of Map 6 P2441
Judgment Value
Malfunction Criteria Threshold Value DTC
Pressure variation value when the LH combination valve is switched < Value of Map 7 P2443
Judgment Value
Malfunction Criteria Threshold Value DTC
Air flow amount when the right bank is closed (value from Map 4) > Value of Map 8 P0411
or
Air flow amount when the left bank is closed (value from Map 5) > Value of Map 9
Map 3
Intake air (g (oz)/rev)
0.1
(0)
0.25
(0.01)
0.3
(0.01)
1
(0.04)
Threshold value (V) 100 100 4.5 4.5
15WRX_STI_US_EN.book 111 ージ 20  
GD(STI)-112
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Map 4
Secondary
air pres-
sure in the
pipe when
both comb.
valve is
closing
kPa
(mmHg,
inHg)
Secondary
air pres-
sure in the
pipe when
LH comb.
valve is
closing
kPa
(mmHg,
inHg)
69.3
(520,
20.5)
74.7
(560,
22)
80
(600,
23.6)
85.3
(640,
25.2)
90.7
(680,
26.8)
96
(720,
28.3)
101.3
(760,
29.9)
106.7
(800,
31.5)
112
(840,
33.1)
117.3
(880,
34.6)
122.7
(920,
36.2)
128
(960,
37.8)
133.3
(1000,
39.4)
138.7
(1040,
40.9)
144
(1080,
42.5)
149.3
(1120,
44.1)
69.3
(520, 20.5)
0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2400 2400 2400
74.7
(560, 22)
–200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2400 2400
80
(600, 23.6)
–400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2400
85.3
(640, 25.2)
–600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400
90.7
(680, 26.8)
–800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200
96
(720, 28.3)
–1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000
101.3
(760, 29.9)
–1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800
106.7
(800, 31.5)
–1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600
112
(840, 33.1)
–1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400
117.3
(880, 34.6)
–1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200
122.7
(920, 36.2)
–2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000
128
(960, 37.8)
–2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800
133.3
(1000, 39.4)
–2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600
138.7
(1040, 40.9)
–2400 –2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400
144
(1080, 42.5)
–2400 –2400 –2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200
149.3
(1120, 44.1)
–2400 –2400 –2400 –2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0
(L/min)
15WRX_STI_US_EN.book 112 ージ 20  
GD(STI)-113
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Map 5
Secondary
air pres-
sure in the
pipe when
both comb.
valve is
closing
kPa
(mmHg,
inHg)
Secondary
air pres-
sure in the
pipe when
RH comb.
valve is
closing
kPa
(mmHg,
inHg)
69.3
(520,
20.5)
74.7
(560,
22)
80
(600,
23.6)
85.3
(640,
25.2)
90.7
(680,
26.8)
96
(720,
28.3)
101.3
(760,
29.9)
106.7
(800,
31.5)
112
(840,
33.1)
117.3
(880,
34.6)
122.7
(920,
36.2)
128
(960,
37.8)
133.3
(1000,
39.4)
138.7
(1040,
40.9)
144
(1080,
42.5)
149.3
(1120,
44.1)
69.3
(520, 20.5)
0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2400 2400 2400
74.7
(560, 22)
–200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2400 2400
80
(600, 23.6)
–400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2400
85.3
(640, 25.2)
–600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400
90.7
(680, 26.8)
–800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200
96
(720, 28.3)
–1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800 2000
101.3
(760, 29.9)
–1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600 1800
106.7
(800, 31.5)
–1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400 1600
112
(840, 33.1)
–1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200 1400
117.3
(880, 34.6)
–1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000 1200
122.7
(920, 36.2)
–2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800 1000
128
(960, 37.8)
–2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600 800
133.3
(1000, 39.4)
–2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400 600
138.7
(1040, 40.9)
–2400 –2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200 400
144
(1080, 42.5)
–2400 –2400 –2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0 200
149.3
(1120, 44.1)
–2400 –2400 –2400 –2400 –2200 –2000 –1800 –1600 –1400 –1200 –1000 –800 –600 –400 –200 0
(L/min)
15WRX_STI_US_EN.book 113 ージ 20  
GD(STI)-114
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CO:DTC P0411 SECONDARY AIR INJECTION SYSTEM INCORRECT FLOW DE-
TECTED
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0410. <Ref. to GD(STI)-108, DTC P0410 SECONDARY AIR IN-
JECTION SYSTEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
Map 6
Amount of intake air when RH comb. valve switches (g (oz)/s)
Battery voltage when RH comb. valve switches (V)
10
(0.35)
15
(0.53)
20
(0.71)
25
(0.88)
26
(0.92)
11 0.025 0.025 0.025 0.005 0
12 0.035 0.035 0.035 0.015 0
13 0.05 0.05 0.05 0.025 0
14 0.05 0.05 0.05 0.025 0
(V)
Map 7
Amount of intake air when LH comb. valve switches (g (oz)/s)
Battery voltage when LH comb. valve switches (V)
10
(0.35)
15
(0.53)
20
(0.71)
25
(0.88)
26
(0.92)
11 0.025 0.025 0.025 0.005 0
12 0.035 0.035 0.035 0.015 0
13 0.05 0.05 0.05 0.025 0
14 0.05 0.05 0.05 0.025 0
(V)
Map 8
Amount of intake air when P0R is measuring (g (oz)/s)
Battery voltage when P0R measuring (V)
2
(0.07)
25
(0.88)
11.5 345 345
12.5 345 345
13.5 345 345
14.5 390 390
15.5 420 420
(L/min)
Map 9
Amount of intake air when P0L is measuring (g (oz)/s)
Battery voltage when P0L measuring (V)
2
(0.07)
25
(0.88)
11.5 345 345
12.5 345 345
13.5 345 345
14.5 390 390
15.5 420 420
(L/min)
15WRX_STI_US_EN.book 114 ージ 20  
GD(STI)-115
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CP:DTC P0413 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE “A”
CIRCUIT OPEN
1. OUTLINE OF DIAGNOSIS
Judge as NG when the ECM output level differs from the actual terminal level.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Secondary air combination valve relay output OFF
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.34 V
15WRX_STI_US_EN.book 115 ージ 20  
GD(STI)-116
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CQ:DTC P0414 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE “A”
CIRCUIT SHORTED
1. OUTLINE OF DIAGNOSIS
Judge as NG when the ECM output level differs from the actual terminal level.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
CR:DTC P0416 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE “B”
CIRCUIT OPEN
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0413. <Ref. to GD(STI)-115, DTC P0413 SECONDARY AIR IN-
JECTION SYSTEM SWITCHING VALVE “A” CIRCUIT OPEN, Diagnostic Trouble Code (DTC) Detecting
Criteria.>
CS:DTC P0417 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE “B”
CIRCUIT SHORTED
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0414. <Ref. to GD(STI)-116, DTC P0414 SECONDARY AIR IN-
JECTION SYSTEM SWITCHING VALVE “A” CIRCUIT SHORTED, Diagnostic Trouble Code (DTC) Detect-
ing Criteria.>
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Secondary air combination valve relay output ON
Judgment Value
Malfunction Criteria Threshold Value
Output current 6 A
15WRX_STI_US_EN.book 116 ージ 20  
GD(STI)-117
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CT:DTC P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the deterioration of the catalyst function.
Though the rear oxygen sensor output changes slowly with a new catalyst, the sensor output with a deteri-
orated catalyst becomes high and the inversion time is shortened.
For this reason, the catalyst diagnosis is carried out by monitoring the rear oxygen sensor output and com-
paring it with the front oxygen (A/F) sensor output.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once at a constant speed of 40 km/h (24.9 MPH) or higher.
(A) Normal (B) Deterioration (C) Output waveform from the front
oxygen (A/F) sensor
(D) Output waveform from the rear
oxygen sensor
(1) Front oxygen (A/F) sensor (2) Rear oxygen sensor (3) Catalytic converter
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Main feedback In operation
Sub feedback In operation
Amount of intake air 10 g/s (0.35 oz/s)
and
< 50 g/s (1.76 oz/s)
Estimated catalyst temperature 450 °C (842 °F)
Vehicle speed > 40 km/h (24.9 MPH)
Rear oxygen output change from 0.55 V or less to 0.55 V or more Experienced after fuel cut
Second diagnosis of P0441 Not in operation
Estimated temperature of the rear oxygen sensor element 500 °C (932 °F)
EN-01713
(A)
(B)
(C) (D)
(1)
(2)
(3)
(3)
15WRX_STI_US_EN.book 117 ージ 20  
GD(STI)-118
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
After the enable conditions have been established, calculate the front oxygen (A/F) sensor lambda value de-
viation sum value (Σ |(sglmd
n
– sglmd
n–1
)|), and rear oxygen sensor output voltage deviation sum value
(Σ |(ro2sad
n
– ro2sad
n–1
)|) in every 32 ms × 4 times. If the front oxygen (A/F) sensor lambda value deviation
sum value (Σ |(sglmd
n
– sglmd
n–1
)|) is the predetermined value or more, calculate the diagnostic value.
If the duration of time while the following conditions are met is within the time indicated, judge as NG.
Time Needed for Diagnosis: 30 — 55 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Σ |(ro2sad
n
– ro2sad
n – 1
)| / Σ |(sglmd
n
– sglmd
n – 1
)| > 8
15WRX_STI_US_EN.book 118 ージ 20  
GD(STI)-119
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CU:DTC P0441 EVAPORATIVE EMISSION CONT. SYS. INCORRECT PURGE
FLOW
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of purge flow by the change of ELCM pressure sensor output value before/after purge
introduction.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis only once after engine start.
4. DIAGNOSTIC METHOD
First diagnosis
Pressure decreases when the purge is introduced compared with when the purge is not performed. By using
this, judge if the purge is correctly performed. If there is no pressure decrease, go to the second diagnosis.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 8 — 38 seconds
Secondary Parameters Enable Conditions
<Common conditions>
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
<First diagnosis>
Total time of canister purge operation 120 s
<Second diagnosis>
Estimated ambient temperature value –25 °C (–13 °F)
Vehicle speed 30 km/h (18.6 MPH)
Main feedback In operation
(1) 0.003 V (2) 1500 ms
Judgment Value
Malfunction Criteria Threshold Value
ELCM pressure sensor output voltage when purge is not performed – ELCM
pressure sensor output voltage when purge is performed
> 0.003 V
The accumulated time while the above conditions are met: cpfokt < 1500 ms
EN-08947
(1)
(2)
purge duty
cpfokt measuring time
Malfunction
Malfunction
Evap. Pressure
cpfokt (timer)
OK
OK
15WRX_STI_US_EN.book 119 ージ 20  
GD(STI)-120
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Second diagnosis
Close the ELCM switching valve, and close the fuel tank completely, and perform the forced purging. If pres-
sure change amount is 0.7 kPa (5 mmHg, 0.2 inHg) or less, judge as malfunction of purge flow.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 21 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) 0.7 kPa (5 mmHg, 0.2 inHg)
Judgment Value
Malfunction Criteria Threshold Value
ELCM pressure value when purge is not performed – ELCM pressure value
when purge is performed
< 0.7 kPa (5 mmHg, 0.2 inHg)
EN-08948
(1)
purge duty
monitoring
Malfunction
OK
ON (Close)
Switching Valve
Evap. Pressure
15WRX_STI_US_EN.book 120 ージ 20  
GD(STI)-121
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CV:DTC P0451 EVAPORATIVE EMISSION SYSTEM PRESSURE SENSOR/
SWITCH RANGE/PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of ELCM pressure sensor output properties.
Judge as NG when the ELCM pressure sensor output value is largely different from the intake manifold pres-
sure when the ignition switch is ON.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis once at ignition ON.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Elapsed time after ignition switch to OFF 500 ms
and
< 60000 ms
Soaking time 60 s
ELCM vacuum pump Not in operation
ELCM switching valve Open
Purge control Not in operation
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 121 ージ 20  
GD(STI)-122
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 320 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
|ELCM pressure sensor output value – intake manifold pressure (absolute pres-
sure) when ignition switch is ON|
> 6532.8 Pa (49 mmHg, 1.9 inHg)
15WRX_STI_US_EN.book 122 ージ 20  
GD(STI)-123
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CW:DTC P0452 EVAPORATIVE EMISSION SYSTEM PRESSURE SENSOR/
SWITCH LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the ELCM pressure sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.973 V
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 123 ージ 20  
GD(STI)-124
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CX:DTC P0453 EVAPORATIVE EMISSION SYSTEM PRESSURE SENSOR/
SWITCH HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the ELCM pressure sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.095 V
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 124 ージ 20  
GD(STI)-125
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
CY:DTC P0455 EVAPORATIVE EMISSION SYSTEM LEAK DETECTED (LARGE
LEAK)
1. OUTLINE OF DIAGNOSIS
This diagnosis judges whether the ELCM operation is normal or not, and whether the evaporative emission
system has leak and clogging or not.
To purge the canister, after driving, perform the five hours soaking after ignition switch OFF in order to sta-
bilize the evaporative gas status. * After 5, 7 or 9.5 hours passed, ECM is activated by soaking timer, and the
leak check is started.
Judges whether the ELCM operation is normal or not, by measuring the reference pressure status via refer-
ence orifice (0.02 inch orifice). Judge as malfunction if the reference pressure is out of specified range. Then,
judge whether there is a leak or not, by comparing the pressure (leak pressure) when the reference pressure
and the evaporative emission system are in negative pressure condition. Judge as system leak in the evap-
orative emission system if the leak pressure is higher than reference pressure. Judge as clogging of pipe if
the leak pressure becomes lower than the reference pressure within the specified amount of time.
0.02 inch leak and 0.04 inch leak can be distinguished by measuring the leak pressure.
The diagnosis results are stored inside ECM until the engine is started again.
*: When the test conditions are not met in 5 hours, perform diagnosis at elapsed time of 7 hours. When the
test conditions are not met in 7 hours, perform diagnosis at elapsed time of 9.5 hours.
OUTLINE OF DIAGNOSIS
Diagnostic item
ELCM system (ELCM body) Vacuum pump stuck
Switching valve stuck to open
Switching valve stuck to close
Reference orifice flow large
Reference orifice flow small
Leak check Large leak
0.04 inch leak
Fuel cap loose
Fuel cap off
System malfunction
Very small leak
0.02 inch leak
Clogging of pipe
EN-08949
ref
P
5 hours after ignition switch turned off.
ECM
Vacuum Pump
Switching Valve
Pressure Sensor
Leak detection pump stuck
Vent valve stuck open
Pipe clogging
OFF
:
Orifice side
OFF
OFF
ON
:
Evap. side
ON
ON
Very small leak
Large leak
Vent valve stuck close
Reference orifice high flow
Reference orifice low flow
ref
P
leak
P
15WRX_STI_US_EN.book 125 ージ 20  
GD(STI)-126
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
2. COMPONENT DESCRIPTION
ELCM consists of the pressure sensor, the reference orifice (diameter of 0.02 inch), the vacuum pump which
introduces the negative pressure into evaporative emission system, and the switching valve which switches
the passage to introduce the negative pressure.
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once when 5, 7 or 9.5 hours has passed after ignition switch is OFF. For more de-
tail, refer to “OUTLINE OF DIAGNOSIS”. <Ref. to GD(STI)-125, OUTLINE OF DIAGNOSIS, DTC P0455
EVAPORATIVE EMISSION SYSTEM LEAK DETECTED (LARGE LEAK), Diagnostic Trouble Code (DTC)
Detecting Criteria.>
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Engine coolant temperature 4.4 °C (39.9 °F)
and
< 45 °C (113 °F)
Accumulated purge amount during previous driving cycle Value of Map 1
Map 1
Engine coolant temperature
°C (°F)
0 (32) 30 (86) 35 (95) 40 (104) 45 (113)
Accumulated purge amount during previous
driving cycle
g (oz)
4000
(141.08)
4000
(141.08)
12000
(423.24)
20000
(705.4)
28000
(987.56)
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 126 ージ 20  
GD(STI)-127
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Mode Explanation of Mode Diagnosis Period
A Vacuum pump operation confirmation and characteristics
stability
7 s or less & 300 s
B Measurement of reference pressure for setting the target
negative pressure
40 s or less
C Switching valve operation confirmation 12 s or less
D Clogging of pipe diagnosis and leak pressure measure-
ment
900 s or less
E Reference pressure measurement for judgment 40 s or less
EN-08950
Activated by soak timer
OFF
:
Orifice side
OFF
OFF
ON
ON
ON
:
Evap. side
Evap. System
target pressure calculation
ABC D E
Judge the leak is occurred or
not by comparing the pressures.
ECM
Vacuum Pump
Switching Valve
Pressure Sensor
Mode
EN-08956
ENABLE
CONDITION
satisfied
not satisfied
Mode
A
Mode
B
Mode
C
Mode
D
Mode
E
OK OK OK OK OK
NGNGNGNGNG
END
15WRX_STI_US_EN.book 127 ージ 20  
GD(STI)-128
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Mode A (Vacuum pump operation confirmation and characteristics stability)
Purpose: Detect the vacuum pump operation trouble.
Judge as NG when the following conditions are established.
Judge as OK if the following conditions are not established, and warm up for five minutes to stabilize the vac-
uum pump characteristics.
Mode B (Measurement of reference pressure for setting the target negative pressure)
1. Purpose: Judge the reference pressure stability.
Judge as NG when the following conditions are established.
2. Purpose: Judge whether the reference pressure is within the normal range, and detect the vacuum pump
and orifice malfunctions.
Judge as NG when the following conditions are established.
Mode C (Switching valve operation confirmation)
Purpose: Measure the pressure increase when switching valve is changed from open to close, and detect the
stuck to open/close malfunctions of the switching valve.
Judge as NG when the following conditions are established.
Judgment Value
Malfunction Criteria Threshold Value DTC
Pressure sensor output value > –224 Pa (–1.68 mmHg, –0.1 inHg) P2404
Judgment Value
Malfunction Criteria Threshold Value DTC
|Pressure sensor maximum output value – Pressure sensor mini-
mum output value|
> 314 Pa (2.355 mmHg, 0.1 inHg) P2404
Judgment Value
Malfunction Criteria Threshold Value DTC
Reference pressure for setting the target negative pressure < Value of Map 2
or
> Value of Map 3
P2404
Map 2
Atmospheric pressure
kPa (mmHg, inHg)
70 (525, 20.7) 80 (600, 23.6) 90 (675, 26.6) 100 (750, 29.5)
Reference pressure for setting the
target negative pressure
kPa (mmHg, inHg)
–4 (–29.79, –1.2) –4.1 (–30.593, –1.2) –4.2 (–31.395, –1.2) –4.3 (–32.19, –1.3)
Map 3
Atmospheric pressure
kPa (mmHg, inHg)
70 (525, 20.7) 80 (600, 23.6) 90 (675, 26.6) 100 (750, 29.5)
Reference pressure for setting the
target negative pressure
kPa (mmHg, inHg)
–0.9 (–7.065, –0.3) –1 (–7.86, –0.3) –1.2 (–8.663, –0.3) –1.3 (–9.465, –0.4)
Judgment Value
Malfunction Criteria Threshold Value DTC
Pressure sensor output value – Reference pressure for setting the
target negative pressure
< 224 Pa (1.68 mmHg, 0.1 inHg) P2404
15WRX_STI_US_EN.book 128 ージ 20  
GD(STI)-129
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Mode D (Clogging of pipe diagnosis and leak pressure measurement)
1. Clogging of pipe
Purpose: Measure the time required for the evaporative emission system to reach the target negative
pressure by the vacuum pump, and detect the clogging of pipe trouble.
Judge as clogging of pipe malfunction if the evaporative emission system reaches to the target negative
pressure within the specified time.
2. Leak pressure measurement
Purpose: Measure the pressure (leak pressure) when the evaporative emission system becomes the neg-
ative pressure by the vacuum pump.
Store the pressure as a leak pressure while the following conditions are met.
Judgment Value
Malfunction Criteria Threshold Value DTC
Time required to reach to the target negative pressure 27000 ms P1451
For target vacuum, use one of the followings.
• Reference pressure for target vacuum setting – value of Map 4
• –5 kPa (–37.298 mmHg, –1.5 inHg)
Map 4
Time of
negative
pressure
introduc-
tion
ms
0 100000 200000 300000 400000 500000 600000 700000 800000 900000 1000000 1100000 1200000
Refer-
ence pres-
sure for
setting the
target neg-
ative pres-
sure –
Pressure
sensor
output
value
kPa
(mmHg,
inHg)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
0.9
(7.058,
0.3)
Judgment Value
Conditions for storing the leak pressure Threshold Value
When any one of the followings is established:
• Reference pressure for setting the target negative pressure – Pressure sensor
output value
Value of Map 4
• Pressure sensor output value < –5 kPa (–37.298 mmHg, –1.5 inHg)
• Time of negative pressure introduction 900000 ms
15WRX_STI_US_EN.book 129 ージ 20  
GD(STI)-130
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Mode E (Measurement of reference pressure for judgment)
1. Purpose: Judge the reference pressure stability.
Judge as NG when the following conditions are established.
2. Purpose: Judge whether the reference pressure is within the normal range, and detect the vacuum pump
and orifice malfunctions. Judge the vacuum pump performance stability.
Judge as NG when the following conditions are established.
3. Purpose: Judge the presence of evaporative emission system leak.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Approx. 23 min
At next engine start, confirm whether the enable conditions are satisfied even though refueling has been
done during soaking, and determine the malfunction.
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
CZ:DTC P0456 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECT-
ED (VERY SMALL LEAK)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0455. <Ref. to GD(STI)-125, DTC P0455 EVAPORATIVE EMIS-
SION SYSTEM LEAK DETECTED (LARGE LEAK), Diagnostic Trouble Code (DTC) Detecting Criteria.>
Judgment Value
Malfunction Criteria Threshold Value DTC
|Pressure sensor maximum output value – Pressure sensor mini-
mum output value|
> 314 Pa (2.355 mmHg, 0.1 inHg) P2404
Judgment Value
Malfunction Criteria Threshold Value DTC
Reference pressure for judgment < Value of Map 5
or
> Value of Map 6
P2404
Map 5
Atmospheric pressure
kPa (mmHg, inHg)
70 (525, 20.7) 80 (600, 23.6) 90 (675, 26.6) 100 (750, 29.5)
Reference pressure for judgment
kPa (mmHg, inHg)
–4.5 (–34.02, –1.3) –4.6 (–34.815, –1.4) –4.7 (–35.618, –1.4) –4.9 (–36.42, –1.4)
Map 6
Atmospheric pressure
kPa (mmHg, inHg)
70 (525, 20.7) 80 (600, 23.6) 90 (675, 26.6) 100 (750, 29.5)
Reference pressure for judgment
kPa (mmHg, inHg)
–0.8 (–6.18, –0.2) –0.9 (–6.983, –0.3) –1 (–7.785, –0.3) –1.1 (–8.58, –0.3)
Judgment Value
Malfunction Criteria Threshold Value DTC
<Large leak (0.04 inch)> P0455
Leak pressure
lleakjdg = (Reference pressure for judgment) × 0.377 – (–45.5 Pa)
lleakjdg (Pa)
<Very small leak (0.02 inch)> P0456
Leak pressure < lleakjdg (Pa)
15WRX_STI_US_EN.book 130 ージ 20  
GD(STI)-131
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DA:DTC P0458 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE
CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the purge control solenoid valve.
Judge as NG when the ECM output level differs from the actual terminal level.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after the conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) To canister (B) To intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Duty ratio of “ON” < 0.75
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.34 V
(A)(B)
EN-02197
15WRX_STI_US_EN.book 131 ージ 20  
GD(STI)-132
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DB:DTC P0459 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE
CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the purge control solenoid valve.
Judge as NG when the ECM output level differs from the actual terminal level.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after the conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) To canister (B) To intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Duty ratio of “ON” 0.25
Judgment Value
Malfunction Criteria Threshold Value
Output current 12 A
(A)(B)
EN-02197
15WRX_STI_US_EN.book 132 ージ 20  
GD(STI)-133
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DC:DTC P0461 FUEL LEVEL SENSOR “A” CIRCUIT RANGE/PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Detect malfunctions of the fuel level sensor output property.
If the fuel level does not vary in a particular driving condition / engine condition where it should, judge as NG.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Less than 1 second
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) Fuel level (B) Resistance
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 5000 ms
Accumulated amount of intake air 165375 g (5832.78 oz)
Judgment Value
Malfunction Criteria Threshold Value
Max. – min. values of fuel level output < 2.6 2 (0.69 US gal, 0.57 Imp gal)
EN-01734
0
(B)
(A)
15WRX_STI_US_EN.book 133 ージ 20  
GD(STI)-134
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DD:DTC P0462 FUEL LEVEL SENSOR “A” CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of fuel level sensor. Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) Engine control module (ECM) (3) Fuel level sensor (5) Combination meter
(2) Fuel sub level sensor (4) Detecting circuit
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 3000 ms
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 2.211 V
(5)
(4)
(1)
(2) (3)
EN-10516
15WRX_STI_US_EN.book 134 ージ 20  
GD(STI)-135
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DE:DTC P0463 FUEL LEVEL SENSOR “A” CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of fuel level sensor. Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(1) Engine control module (ECM) (3) Fuel level sensor (5) Combination meter
(2) Fuel sub level sensor (4) Detecting circuit
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 12 V
(5)
(4)
(1)
(2) (3)
EN-10516
15WRX_STI_US_EN.book 135 ージ 20  
GD(STI)-136
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DF:DTC P04AC EVAP SYSTEM PURGE CONTROL VALVE "B" CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the purge control solenoid valve 2.
Judge as NG when the ECM output level differs from the actual terminal level.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 1 s
Purge control solenoid valve 2 drive signal OFF
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.34 V
15WRX_STI_US_EN.book 136 ージ 20  
GD(STI)-137
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DG:DTC P04AD EVAP SYSTEM PURGE CONTROL VALVE "B" CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the purge control solenoid valve 2.
Judge as NG when the ECM output level differs from the actual terminal level.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 1 s
Purge control solenoid valve 2 drive signal ON
Judgment Value
Malfunction Criteria Threshold Value
Output current 12 A
15WRX_STI_US_EN.book 137 ージ 20  
GD(STI)-138
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DH:DTC P04DB CRANKCASE VENTILATION SYSTEM DISCONNECTED
1. OUTLINE OF DIAGNOSIS
Detect the blow-by hose disconnection abnormality.
Judge as NG when the diagnosis terminal voltage is high.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
(1) Engine control module (ECM) (3) PCV diagnosis connector (4) 5 V
(2) Detecting circuit
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Engine speed 500 rpm
Judgment Value
Malfunction Criteria Threshold Value
Positive crankcase ventilation diagnosis voltage 5.9 V
EN-01790
E
(1)
(2)
(3)
(4)
15WRX_STI_US_EN.book 138 ージ 20  
GD(STI)-139
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DI: DTC P0500 VEHICLE SPEED SENSOR “A”
1. OUTLINE OF DIAGNOSIS
Judge as NG when outside of the judgment value.
Judge NG when the received data from VDCCM&H/U is abnormal vehicle speed, and the vehicle speed data
is impossible.
2. COMPONENT DESCRIPTION
Vehicle speed signals are taken in to the VDC control module and hydraulic control unit, and normal/errone-
ous data of the ABS wheel speed sensor is received by CAN communication from the VDC control module
and hydraulic control unit.
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Speed of RH wheel received from VDC control module & hydraulic control unit 300 km/h (186.4 MPH)
15WRX_STI_US_EN.book 139 ージ 20  
GD(STI)-140
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DJ:DTC P0506 IDLE AIR CONTROL SYSTEM RPM LOWER THAN EXPECTED
1. OUTLINE OF DIAGNOSIS
Detect the malfunction that actual engine speed is not close to target engine speed during idling. Judge as
NG when actual engine speed is not close to target engine speed during idling.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously at idling after warming up engine.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 15 s × 1 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Lambda value (left and right) 0.85
and
< 1.151
Vehicle speed 0 km/h (0 MPH)
Fuel level 9 2 (2.38 US gal, 1.98 Imp gal)
Engine coolant temperature 60 °C (140 °F)
Elapsed time after starting the engine 10.49 s
Accelerator pedal position = 0%
After intake manifold pressure changes by 4 kPa (30 mmHg, 1.2 inHg) or more. > 5.1 s
Elapsed time after switching neutral position switch to ON/OFF > 5.1 s
Cold start diagnosis Not in operation
Judgment Value
Malfunction Criteria Threshold Value
Actual engine speed – Targeted engine speed < –100 rpm
15WRX_STI_US_EN.book 140 ージ 20  
GD(STI)-141
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DK:DTC P0507 IDLE AIR CONTROL SYSTEM RPM HIGHER THAN EXPECTED
1. OUTLINE OF DIAGNOSIS
Detect the malfunction that actual engine speed is not close to target engine speed during idling. Judge as
NG when actual engine speed is not close to target engine speed during idling.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously at idling after warming up engine.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 15 s × 1 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Lambda value (left and right) 0.85
and
< 1.151
Vehicle speed 0 km/h (0 MPH)
Fuel level 9 2 (2.38 US gal, 1.98 Imp gal)
Engine coolant temperature 60 °C (140 °F)
Elapsed time after starting the engine 10.49 s
Accelerator pedal position = 0%
After intake manifold pressure changes by 4 kPa (30 mmHg, 1.2 inHg) or more. > 5.1 s
Elapsed time after switching neutral position switch to ON/OFF > 5.1 s
Cold start diagnosis Not in operation
Judgment Value
Malfunction Criteria Threshold Value
Actual engine speed – Targeted engine speed > 200 rpm
15WRX_STI_US_EN.book 141 ージ 20  
GD(STI)-142
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DL:DTC P050A COLD START IDLE AIR CONTROL SYSTEM PERFORMANCE
1. OUTLINE OF DIAGNOSIS
When cold, the abnormality in the control of target engine speed increase is detected. (P050A)
Idle speed diagnosis
Judge as NG when actual engine speed is not close to target engine speed at cold start.
Detect malfunctions of the catalyst advanced idling retard angle control. (P050B)
Judge as NG when ECM is not controlling the angle properly during catalyst advanced idling retard angle
control.
Final ignition timing diagnosis
Judge as NG when actual retard amount is under the specified value at cold start.
15WRX_STI_US_EN.book 142 ージ 20  
GD(STI)-143
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
2. ENABLE CONDITIONS
Secondary Parameters Enable Conditions
<Idle speed diagnosis>
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Vehicle speed 2 km/h (1.2 MPH)
Engine coolant temperature 60 °C (140 °F)
Throttle opening angle < 0.37 °
Intake air amount sum value < Value of Map 1
Elapsed time after gear position change
(P ←→ D or N ←→ D)
3000 ms
Elapsed time after starting the engine 2000 ms
<Final ignition timing diagnosis>
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Vehicle speed 2 km/h (1.2 MPH)
Engine coolant temperature 60 °C (140 °F)
Throttle opening angle < 0.37 °
Intake air amount sum value < Value of Map 2
Elapsed time after gear position change
(P ←→ D or N ←→ D)
3000 ms
Target retard amount Value from Map 3
Map 1
Engine coolant temperature at engine
starting
°C (°F)
–40
(–40)
–30
(–22)
–20
(–4)
–10
(14)
0
(32)
10
(50)
20
(68)
30
(86)
Intake air amount sum value
g (oz)
950
(33.51)
925
(32.62)
900
(31.74)
870
(30.68)
840
(29.63)
620
(21.87)
420
(14.81)
310
(10.93)
Engine coolant temperature at engine
starting
°C (°F)
40
(104)
50
(122)
60
(140)
70
(158)
80
(176)
90
(194)
100
(212)
110
(230)
Intake air amount sum value
g (oz)
260
(9.17)
210
(7.41)
170 (6) 170 (6) 170 (6) 170 (6) 170 (6) 170 (6)
Map 2
Engine coolant temperature at engine
starting
°C (°F)
–40
(–40)
–30
(–22)
–20
(–4)
–10
(14)
0
(32)
10
(50)
20
(68)
30
(86)
Intake air amount sum value
g (oz)
950
(33.51)
925
(32.62)
900
(31.74)
870
(30.68)
840
(29.63)
620
(21.87)
420
(14.81)
310
(10.93)
Engine coolant temperature at engine
starting
°C (°F)
40
(104)
50
(122)
60
(140)
70
(158)
80
(176)
90
(194)
100
(212)
110
(230)
Intake air amount sum value
g (oz)
260
(9.17)
210
(7.41)
170 (6) 170 (6) 170 (6) 170 (6) 170 (6) 170 (6)
Map 3
Engine coolant
temperature
–40 °C
(–40 °F)
–30 °C
(–22 °F)
–20 °C
(–4 °F)
–10 °C
(14 °F)
0 °C
(32 °F)
10 °C
(50 °F)
20 °C
(68 °F)
30 °C
(86 °F)
40 °C
(104 °F)
50 °C
(122 °F)
60 °C
(140 °F)
Target retard
amount
6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA
15WRX_STI_US_EN.book 143 ージ 20  
GD(STI)-144
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. GENERAL DRIVING CYCLE
Perform the diagnosis at cold start.
4. DIAGNOSTIC METHOD
Idle speed diagnosis
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 7000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Final ignition timing diagnosis
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 7000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
DM:DTC P050B COLD START IGNITION TIMING PERFORMANCE
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P050A. <Ref. to GD(STI)-142, DTC P050A COLD START IDLE AIR
CONTROL SYSTEM PERFORMANCE, Diagnostic Trouble Code (DTC) Detecting Criteria.>
Judgment Value
Malfunction Criteria Threshold Value
Actual engine speed – Target engine
speed
< Value of Map 4
Map 4
Engine coolant tem-
perature
–40 °C
(–40 °F)
–30 °C
(–22 °F)
–20 °C
(–4 °F)
–10 °C
(14 °F)
0 °C
(32 °F)
10 °C
(50 °F)
20 °C
(68 °F)
30 °C
(86 °F)
40 °C
(104 °F)
50 °C
(122 °F)
60 °C
(140 °F)
Threshold Value
–150
rpm
–150
rpm
–150
rpm
–150
rpm
–150
rpm
–150
rpm
–300
rpm
–300
rpm
–300
rpm
–300
rpm
–300
rpm
Judgment Value
Malfunction Criteria Threshold Value
Final ignition timing – ignition timing during CSERS*
*: Ignition timing during CSERS (Cold Start Emission Reduction Strategy) = Base
ignition timing – retard amount
> Value of Map 5
Map 5
Engine coolant tem-
perature
–40 °C
(–40 °F)
–30 °C
(–22 °F)
–20 °C
(–4 °F)
–10 °C
(14 °F)
0 °C
(32 °F)
10 °C
(50 °F)
20 °C
(68 °F)
30 °C
(86 °F)
40 °C
(104 °F)
50 °C
(122 °F)
60 °C
(140 °F)
Threshold Value 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA 6 °CA
15WRX_STI_US_EN.book 144 ージ 20  
GD(STI)-145
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DN:DTC P0512 STARTER REQUEST CIRCUIT
1. OUTLINE OF DIAGNOSIS
Detect abnormal continuity in the starter SW1.
Judge as ON NG when the starter SW 1 signal remains ON.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 30000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 8 V
Engine speed > 500 rpm
Judgment Value
Malfunction Criteria Threshold Value
Starter SW1 voltage Battery voltage × 0.85 V
15WRX_STI_US_EN.book 145 ージ 20  
GD(STI)-146
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DO:DTC P0560 SYSTEM VOLTAGE
1. OUTLINE OF DIAGNOSIS
Detect the open/short circuit of back-up power supply circuit.
Judge as NG when the backup power voltage is low.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Engine speed 500 rpm
Judgment Value
Malfunction Criteria Threshold Value
Voltage of back-up power supply 2.5 V
15WRX_STI_US_EN.book 146 ージ 20  
GD(STI)-147
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DP:DTC P0604 INTERNAL CONTROL MODULE RANDOM ACCESS MEMORY
(RAM) ERROR
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of microcomputer (RAM).
When there is a problem in the main CPU normal RAM, or the sub CPU normal RAM, judge as NG. Judge
as OK when both are operating properly.
If it is possible to write data to the whole area of RAM in the initial routine, and is possible to read the same
data, it is judged as OK, and if not, NG.
2. ENABLE CONDITIONS
Diagnosis with the initial routine.
3. GENERAL DRIVING CYCLE
Perform the diagnosis immediately after the ignition switch is to ON.
4. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 512 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
ECM initialization Executed
Judgment Value
Malfunction Criteria Threshold Value
Write the specified value into the RAM. Different from written value
15WRX_STI_US_EN.book 147 ージ 20  
GD(STI)-148
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DQ:DTC P0605 INTERNAL CONTROL MODULE READ ONLY MEMORY (ROM)
ERROR
1. OUTLINE OF DIAGNOSIS
Judge as NG when SUM value of ROM is outside the standard value.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis immediately after the ignition switch is to ON.
4. DIAGNOSTIC METHOD
Judge as NG if the criteria below are met.
Time Needed for Diagnosis: Undetermined
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
ECM initialization Executed
Judgment Value
Malfunction Criteria Threshold Value
SUM value of ROM Standard
15WRX_STI_US_EN.book 148 ージ 20  
GD(STI)-149
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DR:DTC P0606 CONTROL MODULE PROCESSOR
1. OUTLINE OF DIAGNOSIS
Judge as NG when the CPU operation is abnormal.
(1) Instruction check
(2) Software flow check
(3) Software monitor check
(4) If the output IC operation is abnormal
(5) CAN register check
2. COMPONENT DESCRIPTION
(1) Throttle position sensor (6) Accelerator pedal position sensor 2 (10) CPU
(2) Throttle position sensor 1 (7) I/F circuit (11) Monitoring IC
(3) Throttle position sensor 2 (8) Amplifier circuit (12) EEPROM
(4) Accelerator pedal position sensor (9) Engine control module (ECM) (13) Output IC
(5) Accelerator pedal position sensor 1
EN-08016
(1)
(4)
(2)
(3)
(5)
(6)
(9)
(7)
(10)
(11)
(7)
(7)
(7)
(8)
(12)
(13)
15WRX_STI_US_EN.book 149 ージ 20  
GD(STI)-150
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis:
(1) — 1: 2 time(s)
(1) — 2: 512 ms
(2): 504 ms
(3): 48 ms
(4): 2500 ms
(5): Less than 1 second
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
(1) — 1 Initial routine
(1) — 2 Ignition switch ON
(1) — 2 Battery voltage 6.2 V
(1) — 2 Electronic throttle control relay ON
(2) Ignition switch ON
(3) Ignition switch ON
(3) Battery voltage 6.2 V
(3) Electronic throttle control relay ON
(4) Ignition switch ON
(5) Initial routine
Judgment Value
Malfunction Criteria Threshold Value
(1) — 1 Instruction value Different from expected value
(1) — 2 Calculated result from CPU and FPU Different from expected value
(2) Process flow result The result and expected value do not match.
(3) High integrated IC motor continuity cut demand Exist
(4) Communication between output driver ICs Not possible to communicate
(5) Writing value to CAN register Read out value
15WRX_STI_US_EN.book 150 ージ 20  
GD(STI)-151
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DS:DTC P060A INTERNAL CONTROL MODULE MONITORING PROCESSOR
PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Judge as NG when the monitoring IC operation is abnormal.
(1) Monitoring IC Disable (motor continuity cut demand) diagnosis
(2) Monitoring IC function diagnosis
(3) Monitoring IC register diagnosis
(4) Count up timer diagnosis
2. COMPONENT DESCRIPTION
(1) Throttle position sensor (6) Accelerator pedal position sensor 2 (10) CPU
(2) Throttle position sensor 1 (7) I/F circuit (11) Monitoring IC
(3) Throttle position sensor 2 (8) Amplifier circuit (12) EEPROM
(4) Accelerator pedal position sensor (9) Engine control module (ECM) (13) Output IC
(5) Accelerator pedal position sensor 1
EN-08016
(1)
(4)
(2)
(3)
(5)
(6)
(9)
(7)
(10)
(11)
(7)
(7)
(7)
(8)
(12)
(13)
15WRX_STI_US_EN.book 151 ージ 20  
GD(STI)-152
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
Judge as NG when one of the following conditions is established.
Time Needed for Diagnosis:
(1): 24 ms
(2): (192 ms – 16 ms) × 9 + 304 ms × 2 time(s)
(3): 8 time(s)
(4): 200 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
(1) Battery voltage 6 V
(1) When CPU intentionally sends motor continuity cut demand
(2) Battery voltage 6 V
(2) CPU intentionally sends incorrect data
(3) Battery voltage 6 V
(4) Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
(1) Main throttle opening angle – Main throttle opening angle at monitoring start 2 °
(2) Monitoring IC motor continuity cut demand Not detected
(3) Monitoring IC register writing value Reading value
(4) Monitoring IC count up timer Does not change
15WRX_STI_US_EN.book 152 ージ 20  
GD(STI)-153
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DT:DTC P060B INTERNAL CONTROL MODULE A/D PROCESSING PERFOR-
MANCE
1. OUTLINE OF DIAGNOSIS
Judge as NG when the A/D converter operation is abnormal.
When the A/D converter operation is abnormal (ADC malfunction)
When the input amplifier circuit of throttle position sensor 1 is abnormal (quadruple amplification problem).
2. COMPONENT DESCRIPTION
(1) Throttle position sensor (6) Accelerator pedal position sensor 2 (10) CPU
(2) Throttle position sensor 1 (7) I/F circuit (11) Monitoring IC
(3) Throttle position sensor 2 (8) Amplifier circuit (12) EEPROM
(4) Accelerator pedal position sensor (9) Engine control module (ECM) (13) Output IC
(5) Accelerator pedal position sensor 1
EN-08016
(1)
(4)
(2)
(3)
(5)
(6)
(9)
(7)
(10)
(11)
(7)
(7)
(7)
(8)
(12)
(13)
15WRX_STI_US_EN.book 153 ージ 20  
GD(STI)-154
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
Judge as NG when one of the following conditions is established.
Time Needed for Diagnosis:
(1): 200 ms
(2): 200 ms
(3): 200 ms
(4): 24 ms
(5): 24 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
(1) Battery voltage 6 V
(2) Battery voltage 6 V
(3) Battery voltage 6 V
(4) Battery voltage 6 V
(4) Main throttle opening angle < Value from Map
(5) Battery voltage 6 V
(5) Main throttle opening angle Value from Map
Map
Battery voltage 7.5 V 8 V
Main throttle opening angle 27.5 ° 31 °
Judgment Value
Malfunction Criteria Threshold Value
(1) A/D voltages for monitoring > 2.7 V
or
< 2.5 V
(2) |Buffer voltage of AD changes – Base voltage of A/D changes| > 0.029296875 V
(3) A/D voltages for monitoring Did not change
(4) |Throttle position sensor ( Main ) – (Amplified throttle position sensor (Main))/4| 3 °
(5) (Amplified throttle position sensor (Main))/4 23.8235 °
15WRX_STI_US_EN.book 154 ージ 20  
GD(STI)-155
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DU:DTC P0616 STARTER RELAY CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Model without push button start
Detect abnormal continuity in the starter SW1.
Judge as OFF NG when the starter SW 1 signal remains OFF.
Model with push button start
Detect abnormal continuity in the starter SW 2.
Judge as OFF NG when the starter SW 2 signal remains OFF.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis only once at engine start.
4. DIAGNOSTIC METHOD
Judge as OFF NG when the following conditions are established.
Time Needed for Diagnosis: Less than 1 second
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 8 V
Engine speed Changes from 0 rpm to 500 rpm or more
Vehicle speed < 1 km/h (0.6 MPH)
Starter relay drive ON
Judgment Value
Malfunction Criteria Threshold Value
Starter SW1 signal (models without push button start) with battery voltage × 0.85
V or more
Starter SW2 signal (models with push button start) with battery voltage × 0.85 V
or more
Not detected
15WRX_STI_US_EN.book 155 ージ 20  
GD(STI)-156
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DV:DTC P0617 STARTER RELAY CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Model without push button start
Detect abnormal continuity in the starter SW1.
Judge as ON NG when the starter SW 1 signal remains ON.
Model with push button start
Detect abnormal continuity in the starter SW 2.
Judge as ON NG when the starter SW 2 signal remains ON.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 30000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 8 V
Engine speed > 500 rpm
Starter relay drive OFF
Judgment Value
Malfunction Criteria Threshold Value
Starter SW 1 signal (model without push button start)
Starter SW 2 signal (model with push button start)
Battery voltage × 0.85 V
15WRX_STI_US_EN.book 156 ージ 20  
GD(STI)-157
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DW:DTC P062F INTERNAL CONTROL MODULE EEPROM ERROR
1. OUTLINE OF DIAGNOSIS
Judge as NG when the EEPROM operation is abnormal. (EEPROM malfunction)
2. COMPONENT DESCRIPTION
(1) Throttle position sensor (6) Accelerator pedal position sensor 2 (10) CPU
(2) Throttle position sensor 1 (7) I/F circuit (11) Monitoring IC
(3) Throttle position sensor 2 (8) Amplifier circuit (12) EEPROM
(4) Accelerator pedal position sensor (9) Engine control module (ECM) (13) Output IC
(5) Accelerator pedal position sensor 1
EN-08016
(1)
(4)
(2)
(3)
(5)
(6)
(9)
(7)
(10)
(11)
(7)
(7)
(7)
(8)
(12)
(13)
15WRX_STI_US_EN.book 157 ージ 20  
GD(STI)-158
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Diagnosis 1
Diagnosis 2
Time Needed for Diagnosis:
Diagnosis 1: 48 ms
Diagnosis 2: 2 times
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Ignition switch ON
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Time needed for storing data in EEPROM 48 ms
Judgment Value
Malfunction Criteria Threshold Value
EEPROM writing Error
15WRX_STI_US_EN.book 158 ージ 20  
GD(STI)-159
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DX:DTC P0685 ECM/PCM POWER RELAY CONTROL CIRCUIT/OPEN
1. OUTLINE OF DIAGNOSIS
Detect the main relay stuck to ON.
Judge as NG when ECM keeps operating for more than predetermined time although the main relay does not
turn to OFF after ignition switch is turned to OFF.
2. COMPONENT DESCRIPTION
The main relay controls current of coils by receiving instructions from the ignition switch and ELCM to switch
ECM to ON/OFF.
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once when the enable conditions are established with the ignition switch OFF
ON.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Main relay OFF instruction
Judgment Value
Malfunction Criteria Threshold Value
ECM status In operation
15WRX_STI_US_EN.book 159 ージ 20  
GD(STI)-160
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DY:DTC P081A STARTER DISABLE CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect abnormal continuity in the starter cut relay.
Judge as NG when the starter cut relay output line is open.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis only once at engine start.
4. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Less than 1 second
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 8 V
Engine speed Changes from 0 rpm to 500 rpm or more
Vehicle speed < 1 km/h (0.6 MPH)
Starter cut relay drive OFF
Judgment Value
Malfunction Criteria Threshold Value
Starter cut relay control signal that exceeds battery voltage × 0.34 V Not detected
15WRX_STI_US_EN.book 160 ージ 20  
GD(STI)-161
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
DZ:DTC P0851 NEUTRAL SWITCH INPUT CIRCUIT LOW (MT MODEL)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of neutral SW.
Judge as NG when there is no change in the neutral SW regardless of driving condition with shift changes
(there should be neutral SW ON/OFF inversion considering the vehicle speed and engine speed).
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously in 2 seconds after starting the engine.
4. DIAGNOSTIC METHOD
Judge NG when the malfunction criteria below are completed determined times or more after the neutral SW
change.
Time Needed for Diagnosis: 3 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Change from driving condition a) to b) = 3 time(s)
a) Engine speed 600 rpm — 900 rpm & Vehicle speed 0 km/h (0 MPH)
b) Engine speed 1400 rpm — 2200 rpm & Vehicle speed 64 km/h (39.8 MPH)
Judgment Value
Malfunction Criteria Threshold Value
Neutral switch output voltage Battery voltage × 0.19 V
15WRX_STI_US_EN.book 161 ージ 20  
GD(STI)-162
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EA:DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT HIGH (MT MODEL)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of neutral SW.
Judge as NG when there is no change in the neutral SW regardless of driving condition with shift changes
(there should be neutral SW ON/OFF inversion considering the vehicle speed and engine speed).
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously in 2 seconds after starting the engine.
4. DIAGNOSTIC METHOD
Judge NG when the malfunction criteria below are completed determined times or more after the neutral SW
change.
Time Needed for Diagnosis: 3 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Change from driving condition a) to b) = 3 time(s)
a) Engine speed 600 rpm — 900 rpm & Vehicle speed 0 km/h (0 MPH)
b) Engine speed 1400 rpm — 2200 rpm & Vehicle speed 64 km/h (39.8 MPH)
Judgment Value
Malfunction Criteria Threshold Value
Neutral switch output voltage Battery voltage × 0.6 V
15WRX_STI_US_EN.book 162 ージ 20  
GD(STI)-163
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EB:DTC P1160 RETURN SPRING FAILURE
1. OUTLINE OF DIAGNOSIS
Judge as NG when the valve is opened more than the default opening angle, but does not move to the close
direction with the motor power stopped.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Ignition switch ON OFF
Ignition switch OFF ON (Only after clearing memory)
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Less than 1 second
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Opener spring (4) Full closed stopper (7) DC motor
(2) Return spring (5) Throttle valve (8) Main and sub throttle position sen-
sor
(3) Intermediate stopper (6) Gear
Secondary Parameters Enable Conditions
Battery voltage 6 V
Ignition switch OFF
Elapsed time after motor continuity OFF = 1.6 s
Judgment Value
Malfunction Criteria Threshold Value
Sensor 1 opening angle with power OFF – Sensor 1 opening angle < 2 °
EN-04463
SS
(8)
(6)
(7)
(5)
(1)
(3)
(2)
(4)
15WRX_STI_US_EN.book 163 ージ 20  
GD(STI)-164
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EC:DTC P1410 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE
STUCK OPEN
1. OUTLINE OF DIAGNOSIS
Always detect abnormality that both combination valve electromagnetic valve and the reed valve are open
failure.
Calculate the integrated value of Max./Min. value and output voltage deviation of the secondary air delivery
pipe pressure sensor output voltage in a given time after engine start. Judge as NG if the integrated value
and the difference between Max. and Min. values are large.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform continuous diagnosis when air flow amount is large during the secondary air pump stop after engine
start.
4. DIAGNOSTIC METHOD
When both combination valve electromagnetic valve and the reed valve are open failure, the failure appears
as pulses in the secondary air delivery pipe pressure sensor output. Detect abnormality by capturing these
pulses using the following method.
Calculate Max./Min. value of the secondary air delivery pipe pressure sensor output voltage and the sum of
the output voltage deviation for the given time. Compare the difference between Max. and Min. values with
threshold value and also compare the sum value with the threshold value. If both values exceed the threshold
value, count up NG counter and then judge as NG if the counter reaches the given times.
Time Needed for Diagnosis: 2000 ms × 20 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Engine speed 500 rpm
Elapsed time after starting the engine 9000 ms
After secondary air system stops 9000 ms
After fuel cut 1000 ms
Judgment Value
Malfunction Criteria Threshold Value
Pipe inner pressure difference between Max. and Min. 0.05 V
Sum of the pipe inner pressure variation value every 4 ms 5 V
15WRX_STI_US_EN.book 164 ージ 20  
GD(STI)-165
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
ED:DTC P1449 EVAPORATIVE EMISSION CONT. SYS. AIR FILTER CLOG
1. OUTLINE OF DIAGNOSIS
Detect the drain filter clogging by the pressure change during purge introduction.
Judge as drain filter clogging malfunction if the pressure in the evaporative emission system piping suddenly
decreases by the purging.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously when purging is performed after 20000 ms have passed since the engine
started.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after starting the engine 20000 ms
• ELCM vacuum pump Not in operation
• ELCM switching valve Open
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 165 ージ 20  
GD(STI)-166
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Calculate the difference between the ELCM pressure sensor output value as of 5 seconds ago and the cur-
rent one, and if the value is greater than judgment value, detect and judge as filter clogging trouble.
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Approx. 5.5 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
EE:DTC P1451 EVAPORATIVE EMISSION CONT. SYS.
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0455. <Ref. to GD(STI)-125, DTC P0455 EVAPORATIVE EMIS-
SION SYSTEM LEAK DETECTED (LARGE LEAK), Diagnostic Trouble Code (DTC) Detecting Criteria.>
Judgment Value
Malfunction Criteria Threshold Value
|Pressure sensor output value as of 5
seconds ago – Current pressure sensor
output value|
> Value from Map
Number of above conditions established > 2 time(s)
Map
Vehicle speed
km/h (MPH)
0 (0)
20
(12.4)
40
(24.9)
60
(37.3)
80
(49.7)
100
(62.1)
120
(74.6)
300
(186.4)
|Pressure sensor output value as of 5 seconds
ago – Current pressure sensor output value|
kPa (mmHg, inHg)
969.3
(7.27,
0.3)
969.3
(7.27,
0.3)
969.3
(7.27,
0.3)
969.3
(7.27,
0.3)
969.3
(7.27,
0.3)
969.3
(7.27,
0.3)
969.3
(7.27,
0.3)
2027.2
(15.21,
0.6)
EN-08951
purge duty
OK
Malfunction
Evap. Pressure
monitoring value
5 seconds
15WRX_STI_US_EN.book 166 ージ 20  
GD(STI)-167
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EF:DTC P2004 INTAKE MANIFOLD RUNNER CONTROL STUCK OPEN (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of tumble generator valve motor function.
Judge open fixing malfunction when the opening degree is large even after finishing the tumble generator
valve closing driving.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 3000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after tumble generator valve “closed” signal output 3200 ms
Judgment Value
Malfunction Criteria Threshold Value
Tumble generator valve opening 64.3 °
15WRX_STI_US_EN.book 167 ージ 20  
GD(STI)-168
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EG:DTC P2005 INTAKE MANIFOLD RUNNER CONTROL STUCK OPEN (BANK 2)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of tumble generator valve motor function.
Judge open fixing malfunction when the opening degree is large even after finishing the tumble generator
valve closing driving.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 3000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after tumble generator valve “closed” signal output 3200 ms
Judgment Value
Malfunction Criteria Threshold Value
Tumble generator valve opening 64.3 °
15WRX_STI_US_EN.book 168 ージ 20  
GD(STI)-169
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EH:DTC P2006 INTAKE MANIFOLD RUNNER CONTROL STUCK CLOSED
(BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of tumble generator valve motor function.
Judge close fixing malfunction when the opening degree is small even after finishing the tumble generator
valve open driving.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 3000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after tumble generator valve “open” signal output 4600 ms
Judgment Value
Malfunction Criteria Threshold Value
Tumble generator valve opening < 64.3 °
15WRX_STI_US_EN.book 169 ージ 20  
GD(STI)-170
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EI: DTC P2007 INTAKE MANIFOLD RUNNER CONTROL STUCK CLOSED
(BANK 2)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of tumble generator valve motor function.
Judge close fixing malfunction when the opening degree is small even after finishing the tumble generator
valve open driving.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 3000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Elapsed time after tumble generator valve “open” signal output 4600 ms
Judgment Value
Malfunction Criteria Threshold Value
Tumble generator valve opening < 64.3 °
15WRX_STI_US_EN.book 170 ージ 20  
GD(STI)-171
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EJ: DTC P2008 INTAKE MANIFOLD RUNNER CONTROL CIRCUIT / OPEN (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of tumble generator valve motor.
Judge as NG when the open signal is sent from IC after tumble generator valve driving IC diagnosis.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 32 ms × 20 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (2) Tumble generator valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Tumble generator valve drive duty 79.17%
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.55 V
E
M
(2)
(1)
EN-09574
15WRX_STI_US_EN.book 171 ージ 20  
GD(STI)-172
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EK:DTC P2009 INTAKE MANIFOLD RUNNER CONTROL CIRCUIT LOW (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of tumble generator valve motor.
Judge as NG when the overcurrent signal is sent from IC after tumble generator valve driving IC diagnosis.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 96 ms × 10 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (2) Tumble generator valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Tumble generator valve instruction Open or Closed
Judgment Value
Malfunction Criteria Threshold Value
Overcurrent signal from driver ON
E
M
(2)
(1)
EN-09574
15WRX_STI_US_EN.book 172 ージ 20  
GD(STI)-173
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EL:DTC P2011 INTAKE MANIFOLD RUNNER CONTROL CIRCUIT / OPEN (BANK 2)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of tumble generator valve motor.
Judge as NG when the open signal is sent from IC after tumble generator valve driving IC diagnosis.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 32 ms × 20 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (2) Tumble generator valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Tumble generator valve drive duty 79.17%
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.55 V
E
M
(2)
(1)
EN-09574
15WRX_STI_US_EN.book 173 ージ 20  
GD(STI)-174
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EM:DTC P2012 INTAKE MANIFOLD RUNNER CONTROL CIRCUIT LOW (BANK 2)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of tumble generator valve motor.
Judge as NG when the overcurrent signal is sent from IC after tumble generator valve driving IC diagnosis.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 96 ms × 10 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (2) Tumble generator valve
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Tumble generator valve instruction Open or Closed
Judgment Value
Malfunction Criteria Threshold Value
Overcurrent signal from driver ON
E
M
(2)
(1)
EN-09574
15WRX_STI_US_EN.book 174 ージ 20  
GD(STI)-175
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EN:DTC P2016 TUMBLE GENERATED VALVE POSITION SENSOR 1 CIRCUIT
LOW
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of tumble generator valve position sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Rotor (3) Voltage (V) (4) Tumble generator valve opening
(°)
(2) Return spring
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.264 V
EN-01768
(3)
(4)
(1) (2)
15WRX_STI_US_EN.book 175 ージ 20  
GD(STI)-176
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EO:DTC P2017 TUMBLE GENERATED VALVE POSITION SENSOR 1 CIRCUIT
HIGH
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of tumble generator valve position sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Rotor (3) Voltage (V) (4) Tumble generator valve opening
(°)
(2) Return spring
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.783 V
EN-01768
(3)
(4)
(1) (2)
15WRX_STI_US_EN.book 176 ージ 20  
GD(STI)-177
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EP:DTC P2021 TUMBLE GENERATED VALVE POSITION SENSOR 2 CIRCUIT
LOW
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of tumble generator valve position sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Rotor (3) Voltage (V) (4) Tumble generator valve opening
(°)
(2) Return spring
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.264 V
EN-01768
(3)
(4)
(1) (2)
15WRX_STI_US_EN.book 177 ージ 20  
GD(STI)-178
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EQ:DTC P2022 TUMBLE GENERATED VALVE POSITION SENSOR 2 CIRCUIT
HIGH
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of tumble generator valve position sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Rotor (3) Voltage (V) (4) Tumble generator valve opening
(°)
(2) Return spring
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage 4.783 V
EN-01768
(3)
(4)
(1) (2)
15WRX_STI_US_EN.book 178 ージ 20  
GD(STI)-179
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
ER:DTC P2088 INTAKE CAMSHAFT POSITION ACTUATOR CONTROL CIRCUIT
LOW (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the oil flow control solenoid valve.
Judge as NG when the current is small even though the duty signal is large.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Oil flow control solenoid valve control duty 99.61 %
Judgment Value
Malfunction Criteria Threshold Value
Oil control solenoid valve control present current < 0.306 A
15WRX_STI_US_EN.book 179 ージ 20  
GD(STI)-180
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
ES:DTC P2089 INTAKE CAMSHAFT POSITION ACTUATOR CONTROL CIRCUIT
HIGH (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of oil flow control solenoid valve.
Judge as NG when the current is large even though the duty signal is small.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Oil flow control solenoid valve control duty < 0.39 %
Judgment Value
Malfunction Criteria Threshold Value
Oil control solenoid valve control present current 0.306 A
15WRX_STI_US_EN.book 180 ージ 20  
GD(STI)-181
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
ET:DTC P2090 EXHAUST CAMSHAFT POSITION ACTUATOR CONTROL CIR-
CUIT LOW (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of the oil flow control solenoid valve.
Judge as NG when the current is small even though the duty signal is large.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Oil flow control solenoid valve control duty 99.61 %
Judgment Value
Malfunction Criteria Threshold Value
Oil control solenoid valve control present current < 0.306 A
15WRX_STI_US_EN.book 181 ージ 20  
GD(STI)-182
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EU:DTC P2091 EXHAUST CAMSHAFT POSITION ACTUATOR CONTROL CIR-
CUIT HIGH (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect open or short circuit of oil flow control solenoid valve.
Judge as NG when the current is large even though the duty signal is small.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Oil flow control solenoid valve control duty < 0.39 %
Judgment Value
Malfunction Criteria Threshold Value
Oil control solenoid valve control present current 0.306 A
15WRX_STI_US_EN.book 182 ージ 20  
GD(STI)-183
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EV:DTC P2092 INTAKE CAMSHAFT POSITION ACTUATOR CONTROL CIRCUIT
LOW (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P2088. <Ref. to GD(STI)-179, DTC P2088 INTAKE CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT LOW (BANK 1), Diagnostic Trouble Code (DTC) Detecting
Criteria.>
EW:DTC P2093 INTAKE CAMSHAFT POSITION ACTUATOR CONTROL CIRCUIT
HIGH (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P2089. <Ref. to GD(STI)-180, DTC P2089 INTAKE CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT HIGH (BANK 1), Diagnostic Trouble Code (DTC) Detecting
Criteria.>
EX:DTC P2094 EXHAUST CAMSHAFT POSITION ACTUATOR CONTROL CIR-
CUIT LOW (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P2090. <Ref. to GD(STI)-181, DTC P2090 EXHAUST CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT LOW (BANK 1), Diagnostic Trouble Code (DTC) Detecting
Criteria.>
EY:DTC P2095 EXHAUST CAMSHAFT POSITION ACTUATOR CONTROL CIR-
CUIT HIGH (BANK 2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P2091. <Ref. to GD(STI)-182, DTC P2091 EXHAUST CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT HIGH (BANK 1), Diagnostic Trouble Code (DTC) Detecting
Criteria.>
15WRX_STI_US_EN.book 183 ージ 20  
GD(STI)-184
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
EZ:DTC P2096 POST CATALYST FUEL TRIM SYSTEM TOO LEAN (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of fuel system from the size of the sub feedback learning value.
Control the sub feedback learning and judge as NG when the learning value is in the lean zone.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously when the vehicle is idling or running at a constant speed of 80 km/h (50
MPH) or more.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1 s
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
(1) Atmosphere (2) Exhaust gas (3) Electromotive force
Secondary Parameters Enable Conditions
Conditions for carrying out the sub feedback learning Completed
Amount of intake air 10 g/s (0.35 oz/s)
Engine load change every 0.5 engine revs. < 0.02 g/rev (0 oz/rev)
Judgment Value
Malfunction Criteria Threshold Value
Sub feedback learning value < –0.042
EN-01696
(3)
V
(1)
(2) (2)
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 184 ージ 20  
GD(STI)-185
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FA:DTC P2097 POST CATALYST FUEL TRIM SYSTEM TOO RICH (BANK 1)
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of fuel system from the size of the sub feedback learning value.
Sub feedback learning is being performed. When the learning value goes to the rich side, judge as NG.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously when the vehicle is idling or running at a constant speed of 80 km/h (50
MPH) or more.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 1 s
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
(1) Atmosphere (2) Exhaust gas (3) Electromotive force
Secondary Parameters Enable Conditions
Conditions for carrying out the sub feedback learning Completed
Amount of intake air 10 g/s (0.35 oz/s)
Engine load change every 0.5 engine revs. < 0.02 g/rev (0 oz/rev)
Judgment Value
Malfunction Criteria Threshold Value
Sub feedback learning value 0.028
EN-01696
(3)
V
(1)
(2) (2)
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 185 ージ 20  
GD(STI)-186
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FB:DTC P2101 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT RANGE/
PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Judge as NG when the motor current becomes large or drive circuit is heated.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 512 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (4) Drive circuit (6) Electronic throttle control relay
(2) Detecting circuit (5) Temperature detection circuit (7) Motor
(3) Overcurrent detection circuit
Secondary Parameters Enable Conditions
Battery voltage 6.2 V
Electronic throttle control relay output ON
Judgment Value
Malfunction Criteria Threshold Value
Overcurrent signal from driver ON
EN-01867
(3)(2)
(5)(2)
(4)
(1)
(6)
(7)
12V 12V
15WRX_STI_US_EN.book 186 ージ 20  
GD(STI)-187
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FC:DTC P2102 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Judge as NG when the electronic throttle control power is not supplied even when ECM sets the electric con-
trol throttle relay to ON.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 352 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (3) Drive circuit (5) Motor
(2) Voltage detection circuit (4) Electronic throttle control relay
Secondary Parameters Enable Conditions
Battery voltage 11 V
Electronic throttle control relay output ON
Judgment Value
Malfunction Criteria Threshold Value
Motor power voltage 5 V
EN-01868
(2)
(3)
(1)
(4)
(5)
12V 12V
15WRX_STI_US_EN.book 187 ージ 20  
GD(STI)-188
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FD:DTC P2103 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Judge as NG when the electronic throttle control power is supplied even when ECM sets the electronic throt-
tle control relay to OFF.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
When ignition switch ON OFF
Ignition switch OFF ON (Only after clearing memory)
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 600 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (3) Drive circuit (5) Motor
(2) Voltage detection circuit (4) Electronic throttle control relay
Secondary Parameters Enable Conditions
Battery voltage 6 V
Electronic throttle control relay output OFF
Judgment Value
Malfunction Criteria Threshold Value
Motor power voltage 5 V
EN-01868
(2)
(3)
(1)
(4)
(5)
12V 12V
15WRX_STI_US_EN.book 188 ージ 20  
GD(STI)-189
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FE:DTC P2109 THROTTLE/PEDAL POSITION SENSOR “A” MINIMUM STOP
PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Judge as NG when full close point learning cannot conducted or abnormal value is detected.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis at full closed point learning.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 8 ms — 80 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (3) Motor (4) Throttle position sensor
(2) Drive circuit
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Throttle sensor opening angle at full close point learning < 9.884 °
or
> 20.116 °
or
Throttle opening angle when the ignition switch is ON – Throttle minimum stop
position
< 1.637 °
EN-01869
(1)
(2)
(3)
(4)
15WRX_STI_US_EN.book 189 ージ 20  
GD(STI)-190
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FF:DTC P2119 THROTTLE ACTUATOR CONTROL THROTTLE BODY RANGE/
PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Judge as NG when the target opening angle and actual opening angle is mismatched or the current to motor
is the specified duty or more for specified time continuously.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously when the electronic throttle control is operating.
(1) Motor (3) Engine control module (ECM) (4) Drive circuit
(2) Throttle position sensor
Secondary Parameters Enable Conditions
Battery voltage 6.2 V
Electronic throttle control relay ON
EN-01863
(3)
(4)
(1)
(2)
15WRX_STI_US_EN.book 190 ージ 20  
GD(STI)-191
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
Judge as NG if the criteria below are met.
Diagnosis 1
Time Needed for Diagnosis:
Engine speed 500 rpm:2000 ms
Engine speed < 500 rpm:5000 ms
Diagnosis 2
Time Needed for Diagnosis:
Engine speed 500 rpm: Refer to Details of Judgment time.
Engine speed < 500 rpm:5000 ms
Details of Judgment Value
Judgment Value
Malfunction Criteria Threshold Value
Output duty to drive circuit 95 %
Judgment Value
Malfunction Criteria Threshold Value
Difference between target opening angle and actual opening angle Within NG range of Details of Judgment
value
(X1) 6.15 ° (X2) 9.65 ° (X3) 14.65 °
(X4) 26.65 °
(Y1) 3.5 ° (Y2) 5 ° (Y3) 12 °
(Y4) 25 °
EN-08055
0
(Y4)
(Y3)
(Y2)
(Y1)
0
(X1) (X2) (X3)
(NG area)
(X4)
(OK area)
Target throttle opening angle ( )
Difference between
target opening angle
and
actual opening angle (
)
15WRX_STI_US_EN.book 191 ージ 20  
GD(STI)-192
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Details of Judgment time
NOTE:
Judgment time is always 1000 milliseconds when actual opening angle < target opening angle.
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(X1) 5.5 ° (X2) 9 ° (X3) 13 °
(X4) 22 °
(Y1) 1000 ms (Y2) 400 ms (Y3) 300 ms
(Y4) 250 ms
EN-08056
0
(Y1)
(Y2)
(Y3)
0
(X1) (X2) (X3) (X4)
(Y4)
Throttle position sensor 1 opening angle (˚)
Judgment time
(milliseconds)
15WRX_STI_US_EN.book 192 ージ 20  
GD(STI)-193
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FG:DTC P2122 THROTTLE/PEDAL POSITION SENSOR/SWITCH “D” CIRCUIT
LOW INPUT
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of accelerator pedal position sensor 1.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 100 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (3) Accelerator pedal position sensor
2 signal
(4) Accelerator pedal position sensor
(2) Accelerator pedal position sensor
1 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 1 input voltage < 0.301 V
EN-01861
(2)
(3)
(4)
(1)
15WRX_STI_US_EN.book 193 ージ 20  
GD(STI)-194
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FH:DTC P2123 THROTTLE/PEDAL POSITION SENSOR/SWITCH “D” CIRCUIT
HIGH INPUT
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of accelerator pedal position sensor 1.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 32 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (3) Accelerator pedal position sensor
2 signal
(4) Accelerator pedal position sensor
(2) Accelerator pedal position sensor
1 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 1 input voltage 4.783 V
EN-01861
(2)
(3)
(4)
(1)
15WRX_STI_US_EN.book 194 ージ 20  
GD(STI)-195
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FI: DTC P2127 THROTTLE/PEDAL POSITION SENSOR/SWITCH “E” CIRCUIT
LOW INPUT
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of accelerator pedal position sensor 2.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 100 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (3) Accelerator pedal position sensor
2 signal
(4) Accelerator pedal position sensor
(2) Accelerator pedal position sensor
1 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 2 input voltage < 0.301 V
EN-01861
(2)
(3)
(4)
(1)
15WRX_STI_US_EN.book 195 ージ 20  
GD(STI)-196
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FJ:DTC P2128 THROTTLE/PEDAL POSITION SENSOR/SWITCH “E” CIRCUIT
HIGH INPUT
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of accelerator pedal position sensor 2.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 100 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) Engine control module (ECM) (3) Accelerator pedal position sensor
2 signal
(4) Accelerator pedal position sensor
(2) Accelerator pedal position sensor
1 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
Judgment Value
Malfunction Criteria Threshold Value
Sensor 2 input voltage 4.783 V
EN-01861
(2)
(3)
(4)
(1)
15WRX_STI_US_EN.book 196 ージ 20  
GD(STI)-197
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FK:DTC P2135 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A”/“B” VOLT-
AGE CORRELATION
1. OUTLINE OF DIAGNOSIS
Judge as NG when the signal level of throttle position sensor 1 is different from the throttle position sensor 2.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
(1) Throttle position sensor 1 signal (3) Throttle position sensor (4) Engine control module (ECM)
(2) Throttle position sensor 2 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
EN-01859
(1)
(2)
(3)
(4)
15WRX_STI_US_EN.book 197 ージ 20  
GD(STI)-198
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Details of Judgment Value
Time Needed for Diagnosis: 212 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Judgment Value
Malfunction Criteria Threshold Value
Signal difference between two sensors Within NG range of Details of Judgment value
(X1) 2.125 ° (X2) 4.25 ° (X3) 9 °
(X4) 31.625 °
(Y1) 5.15 ° (Y2) 6.15 ° (Y3) 8.28 °
(Y4) 10.4 ° (Y5) 12.4 °
EN-08032
(Y5)
(Y4)
(Y3)
(Y1)
(X1) (X2) (X3) (X4)
(Y2)
(OK area)
Throttle position sensor 1 opening angle (˚)
Sensor output
difference (˚)
(NG area)
0
0
15WRX_STI_US_EN.book 198 ージ 20  
GD(STI)-199
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FL:DTC P2138 THROTTLE/PEDAL POSITION SENSOR/SWITCH “D”/“E” VOLT-
AGE CORRELATION
1. OUTLINE OF DIAGNOSIS
Judge as NG when the signal level of accelerator pedal position sensor 1 is different from the accelerator
pedal position sensor 2.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
(1) Engine control module (ECM) (3) Accelerator pedal position sensor
2 signal
(4) Accelerator pedal position sensor
(2) Accelerator pedal position sensor
1 signal
Secondary Parameters Enable Conditions
Battery voltage 6 V
EN-01861
(2)
(3)
(4)
(1)
15WRX_STI_US_EN.book 199 ージ 20  
GD(STI)-200
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Details of Judgment Value
Time Needed for Diagnosis: 116 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Judgment Value
Malfunction Criteria Threshold Value
Signal difference between two sensors Within NG range of Details of Judgment value
(X1) 0.6 ° (X2) 1.2 ° (X3) 2 °
(X4) 4 °
(Y1) 1.465 ° (Y2) 1.597 ° (Y3) 1.663 °
(Y4) 2.455 ° (Y5) 3.116 °
0
(Y5)
(Y4)
(Y3)
(Y1)
0
(X1) (X2) (X3) (X4)
(Y2)
EN-10888
Sensor output
difference (˚)
Accelerator pedal position sensor 2 opening angle (˚)
(NG area)
(OK area)
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GD(STI)-201
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FM:DTC P2158 VEHICLE SPEED SENSOR "B"
1. OUTLINE OF DIAGNOSIS
Judge as NG when outside of the judgment value.
Judge NG when the received data from VDCCM&H/U is abnormal vehicle speed, and the vehicle speed data
is impossible.
2. COMPONENT DESCRIPTION
Vehicle speed signals are taken in to the VDC control module and hydraulic control unit, and normal/errone-
ous data of the ABS wheel speed sensor is received by CAN communication from the VDC control module
and hydraulic control unit.
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Speed of LH wheel received from VDC control module & hydraulic control unit 300 km/h (186.4 MPH)
15WRX_STI_US_EN.book 201 ージ 20  
GD(STI)-202
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FN:DTC P2195 O2 SENSOR SIGNAL BIASED/STUCK LEAN (BANK 1 SENSOR
1)
1. OUTLINE OF DIAGNOSIS
Detect that λ value remains low.
Judge as NG when lambda value is abnormal in accordance with λ value of front oxygen (A/F) sensor and
running conditions such as vehicle speed, amount of intake air, engine coolant temperature, sub feedback
control, etc.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
λ value = Actual air fuel ratio/Theoretical air fuel ratio
λ > 1: Lean
λ < 1: Rich
(A) Electromotive force (B) Air fuel ratio (C) Rich
(D) Lean
(1) Exhaust gas (2) ZrO
2
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Atmospheric pressure > 75.1 kPa (563 mmHg, 22.2 inHg)
Vehicle speed 0 km/h (0 MPH)
Amount of intake air 6 g/s (0.21 oz/s)
Rear oxygen sensor sub feedback Execution
Rear oxygen sensor output voltage – Feedback target voltage – 0.2 V — 0.1 V
or
Rear oxygen sensor sub feedback compensation coefficient On Min.
or
Rear oxygen sensor sub feedback compensation coefficient On Max.
EN-09361
(C) (B) (D)
(A)
(2)
(1)(1)
15WRX_STI_US_EN.book 202 ージ 20  
GD(STI)-203
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
4. GENERAL DRIVING CYCLE
Perform diagnosis continuously at a constant speed of 0 km/h (0 MPH) or more after 0 ms have passed since
the engine started.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 10000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
λ value 0.85
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GD(STI)-204
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FO:DTC P2196 O2 SENSOR SIGNAL BIASED/STUCK RICH (BANK 1 SENSOR 1)
1. OUTLINE OF DIAGNOSIS
Detect that λ value remains high.
Judge as NG when lambda value is abnormal in accordance with λ value of front oxygen (A/F) sensor and
running conditions such as vehicle speed, amount of intake air, engine coolant temperature, sub feedback
control, etc.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform diagnosis continuously at a constant speed of 0 km/h (0 MPH) or more after 0 ms have passed since
the engine started.
λ value = Actual air fuel ratio/Theoretical air fuel ratio
λ > 1: Lean
λ < 1: Rich
(A) Electromotive force (B) Air fuel ratio (C) Rich
(D) Lean
(1) Exhaust gas (2) ZrO
2
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Atmospheric pressure > 75.1 kPa (563 mmHg, 22.2 inHg)
Vehicle speed 0 km/h (0 MPH)
Amount of intake air 6 g/s (0.21 oz/s)
Rear oxygen sensor sub feedback Execution
Rear oxygen sensor output voltage – Feedback target voltage – 0.2 V — 0.1 V
or
Rear oxygen sensor sub feedback compensation coefficient On Min.
or
Rear oxygen sensor sub feedback compensation coefficient On Max.
EN-09361
(C) (B) (D)
(A)
(2)
(1)(1)
15WRX_STI_US_EN.book 204 ージ 20  
GD(STI)-205
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 10000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
λ value 1.15
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GD(STI)-206
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FP:DTC P219A BANK 1 AIR-FUEL RATIO IMBALANCE
1. OUTLINE OF DIAGNOSIS
This diagnostic monitor performs a functional check of the fuel system to determine an air-fuel ratio cylinder
imbalance.
This diagnosis is composed of two monitors.
The outline of “monitor A1” is as follows. When an air-fuel ratio cylinder imbalance occurs, the primary oxy-
gen sensor output signal will oscillate with increased amplitude. This monitor utilizes this behavior to make
a diagnosis. The monitor integrates the difference between the amplification value and the mean value of the
first oxygen sensor output signal and compares it to a threshold to make a judgment.
The outline of “monitor B1” is as follows. Similarly, when an imbalance occurs, the engine speed also fluctu-
ates with increased amplitude. This monitor utilizes this behavior to make a diagnosis. For reference, it
should be noted that this imbalance monitor method is actually similar to the current misfire diagnostic mon-
itor, and the parameter “domg360” (units: degrees CA) is shared between the imbalance and misfire moni-
tors. The imbalance monitor is performed during idle condition when the engine is warm. The monitor
integrates the count of “domg360” which exceeds a threshold in 1000 revolution.
When both the “monitor A1” value and the “monitor B1” value exceed a predetermined threshold, this monitor
determines a malfunction and stores a fault code.
15WRX_STI_US_EN.book 206 ージ 20  
GD(STI)-207
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Monitor A1
When there is an air-fuel ratio cylinder imbalance malfunction, the primary oxygen sensor output fluctuates
widely compared with a normal sensor, as shown by the chain line in Figure 1 below. This monitor makes a
diagnosis based on this phenomenon. Each primary oxygen sensor signal (PS) and mean value of the pri-
mary oxygen sensor signal (MS) is calculated from the primary oxygen sensor signal. The absolute values
of (PS – MS) are sampled every 4 ms as shown in the figure. Diagnostic value 1 (DV1) is obtained by inte-
grating the absolute value of (PS – MS) for 2500 times. A malfunction is determined when DV1 exceeds the
threshold. The judgment values are determined experimentally.
Figure 1. Compare malfunctioned primary oxygen sensor output with a normal sensor
EN-09840
1cycle (720deg)
PS: Primary oxygen sensor signal
MS: Mean value of the primary
oxygen sensor output signal
Time
PS
Crank angle (degree)
Sampling period
(4ms)
PS
MS
MS
Malfunction criteria : DV1 > Threshold
PS0
PS1
MS0
MS1
Diagnostic value 1 (DV1) = [n=2500]
n-1
k=0
kk
|MS-PS|
MS
k
= (PS
k
– MS
k-1
) x 1/4 + MS
k-1
Malfunction
Normal
15WRX_STI_US_EN.book 207 ージ 20  
GD(STI)-208
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Monitor B1
Method used: Difference method of 360 degrees CA
Monitor value: domg360 = (omg 1 – omg 0) – (omg 3 – omg 2) = angular speed
Each crankshaft angular speed is defined as Figure 2 below.
Figure 2. Description of domg360 output
This method uses the fact that the domg360 of lean conditioned cylinder caused by imbalance malfunction
indicates big value, as shown by the chain line in Figure 3 below.
The number of times for domg360 to exceed the judgment value in 1000 revolutions (500 cycles) is calculat-
ed as diagnostic value 2 (DV2). A malfunction is determined when DV2 exceeds the threshold.
Figure 3. Compare malfunctioned domg360 output with a normal output
EN-09841
Cyl #1Firing order
omg X = Crankshaft angular speed
X = Sampling timing
For example omg0 = Crankshaft angular speed at the current sampling timing
5 lgnition events before 1 lgnition events before
Current lgnition
lgnition events
Crankshaft
angular
speed
Description
Cyl #3 Cyl #2 Cyl #4 Cyl #1 Cyl #3
omg5 omg4 omg3 omg2 omg1 omg0
Cyl #2
Malfunction criteria : DV2 > Threshold
Diagnostic value 2 (DV2) : The number of times for domg360 to exceed the judgment value.
Malfunction
Diagnostic value2
Normal
domg360
1cycle 1cycle
Cyl #4
Cyl #3
Cyl #1
Cyl #2
Judgement value
EN-09842
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GD(STI)-209
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
Monitor A1: Primary oxygen sensor fluctuation
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Atmospheric pressure 75.1 kPa (563 mmHg, 22.2 inHg)
Closed loop control with primary oxygen sensor Active
Engine speed > 1600 rpm
and
< 3200 rpm
Intake air mass 0.80 g/rev (0.03 oz/rev)
Monitor B1: Crankshaft speed fluctuation
Secondary Parameters Enable Conditions
Misfire diagnosis monitor Active
Accelerator pedal position = 0%
Vehicle speed 2 km/h (1.2 MPH)
Engine speed > 550 rpm
and
< 1065 rpm
Intake air mass per revolution > 0 g/rev (0 oz/rev)
and
< 10 g/rev (0.35 oz/rev)
15WRX_STI_US_EN.book 209 ージ 20  
GD(STI)-210
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
4. DIAGNOSTIC METHOD
Judge as NG when Monitor A1 and Monitor B1 are both NG, and when either is OK, judge as OK.
Monitor A1
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 4 ms × 2500 time(s)
Monitor B1
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 500 engine revs.
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Diagnostic value 1 (DV1) > Threshold value 1 (TV1)
EN-09888
Threshold value 1 (TV1):
[n=2500]
n-1
k=0
k
Map
Map
Engine load (g/rev (oz/rev))
0.8 (0.03) 0.9 (0.03) 1 (0.04) 1.1 (0.04) 1.2 (0.04) 1.3 (0.05) 1.4 (0.05) 1.5 (0.05)
Engine
speed
(rpm)
1600 0.0069 0.0088 0.0073 0.0078 0.0080 0.0081 0.0087 0.0087
1800 0.0077 0.0084 0.0074 0.0072 0.0076 0.0074 0.0074 0.0074
2000 0.0074 0.0079 0.0077 0.0080 0.0082 0.0087 0.0087 0.0087
2200 0.0060 0.0081 0.0088 0.0061 0.0056 0.0061 0.0059 0.0059
2400 0.0059 0.0065 0.0073 0.0082 0.0062 0.0063 0.0067 0.0073
2600 0.0036 0.0053 0.0064 0.0051 0.0079 0.0078 0.0068 0.0071
2800 0.0045 0.0042 0.0046 0.0056 0.0063 0.0062 0.0076 0.0081
3000 0.0062 0.0062 0.0073 0.0075 0.0073 0.0081 0.0071 0.0078
3200 0.0049 0.0066 0.0073 0.0073 0.0076 0.0076 0.0079 0.0079
Judgment Value
Malfunction Criteria Threshold Value
Diagnostic Value2 (DV2) > 14 time(s)
15WRX_STI_US_EN.book 210 ージ 20  
GD(STI)-211
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FQ:DTC P2257 AIR SYSTEM CONTROL "A" CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Judge as NG when the ECM output level differs from the actual terminal level.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Secondary air pump drive signal OFF
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.34 V
15WRX_STI_US_EN.book 211 ージ 20  
GD(STI)-212
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FR:DTC P2258 AIR SYSTEM CONTROL "A" CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Judge as NG when the ECM output level differs from the actual terminal level.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Secondary air pump drive signal ON
Judgment Value
Malfunction Criteria Threshold Value
Output current 12 A
15WRX_STI_US_EN.book 212 ージ 20  
GD(STI)-213
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FS:DTC P2270 O2 SENSOR SIGNAL BIASED/STUCK LEAN (BANK 1 SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the stuck of rear oxygen sensor voltage in lean state.
When rear oxygen sensor voltage remains below the threshold value for predetermined time, diagnosis in-
terrupts target air fuel ratio for control and raises output voltage.
Judge as NG detecting the stuck in lean state when rear oxygen sensor voltage remains below the threshold
value even after the interrupt control.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after the enable conditions have been established.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Sub feedback In operation
Amount of intake air 10 g/s (0.35 oz/s)
Estimated temperature of the rear oxygen sensor element 500 °C (932 °F)
Enable conditions at interrupt control are as follows
Air fuel ratio reduced from target air fuel ratio = Value of Map
Continuous time when rear oxygen sensor output voltage is less than 0.55 V 15000 ms
Map
Output voltage of rear oxygen sensor
V
0.000 0.100 0.200 0.400 0.600
Air fuel ratio reduced from target air fuel ratio
%
–0.15 –0.15 –0.04 –0.04 –0.04
EN-10447
(E)
(F)
(C) (B) (D)
(A)
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GD(STI)-214
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 25000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Output voltage of rear oxygen sensor < 0.55 V
15WRX_STI_US_EN.book 214 ージ 20  
GD(STI)-215
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FT:DTC P2271 O2 SENSOR SIGNAL BIASED/STUCK RICH (BANK 1 SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect the stuck of rear oxygen sensor voltage in rich state.
Detect the stuck in rich state and judge as NG if rear oxygen sensor voltage remains above the threshold val-
ue for predetermined time.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
(A) Electromotive force (B) Air fuel ratio (C) Lean
(D) Rich (E) Theoretical air fuel ratio (F) Comparative voltage
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Deceleration fuel cut for 5000 ms or more. Experienced
Estimated temperature of the rear oxygen sensor element 500 °C (932 °F)
Judgment Value
Malfunction Criteria Threshold Value
Output voltage of rear oxygen sensor > 0.15 V
EN-10447
(E)
(F)
(C) (B) (D)
(A)
15WRX_STI_US_EN.book 215 ージ 20  
GD(STI)-216
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FU:DTC P2401 EVAPORATIVE EMISSION SYSTEM LEAK DETECTION PUMP
CONTROL CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the ELCM vacuum pump.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
ELCM vacuum pump drive signal OFF
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.34 V
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 216 ージ 20  
GD(STI)-217
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FV:DTC P2402 EVAPORATIVE EMISSION SYSTEM LEAK DETECTION PUMP
CONTROL CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the ELCM vacuum pump.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
ELCM vacuum pump drive signal ON
Judgment Value
Malfunction Criteria Threshold Value
Output current 12 A
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 217 ージ 20  
GD(STI)-218
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FW:DTC P2404 EVAPORATIVE EMISSION SYSTEM LEAK DETECTION PUMP
SENSE CIRCUIT RANGE/PERFORMANCE
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0455. <Ref. to GD(STI)-125, DTC P0455 EVAPORATIVE EMIS-
SION SYSTEM LEAK DETECTED (LARGE LEAK), Diagnostic Trouble Code (DTC) Detecting Criteria.>
15WRX_STI_US_EN.book 218 ージ 20  
GD(STI)-219
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FX:DTC P2419 EVAPORATIVE EMISSION SYSTEM SWITCHING VALVE CON-
TROL CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the ELCM switching valve.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
ELCM switching valve drive signal OFF
Judgment Value
Malfunction Criteria Threshold Value
Output voltage Battery voltage × 0.34 V
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 219 ージ 20  
GD(STI)-220
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FY:DTC P2420 EVAPORATIVE EMISSION SYSTEM SWITCHING VALVE CON-
TROL CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the ELCM switching valve.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after the enable conditions have been established.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
(1) ELCM (5) Vacuum pump (9) Fuel tank
(2) Switching valve (6) Drain filter (10) Canister
(3) Reference orifice (0.02 inch ori-
fice)
(7) Purge control solenoid valve
(4) Pressure sensor (8) Intake manifold
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
ELCM switching valve drive signal ON
Judgment Value
Malfunction Criteria Threshold Value
Output current 12 A
EN-08957
M
(10)
(8)
(6)(5)
(2)
(3)
(4)
(1)
(7)
(9)
15WRX_STI_US_EN.book 220 ージ 20  
GD(STI)-221
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
FZ:DTC P2431 SECONDARY AIR INJECTION SYSTEM AIR FLOW /PRESSURE
SENSOR CIRCUIT RANGE/PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Detect the malfunction of secondary air pressure sensor output property.
Judge as NG when the secondary air pressure sensor output is largely different from the intake manifold
pressure at engine start.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Perform the diagnosis with ignition switch ON.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 320 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Secondary Parameters Enable Conditions
Elapsed time after ignition switch to OFF < 60000 ms
Soaking time 60 s
After secondary air system stops 3000 ms
Judgment Value
Malfunction Criteria Threshold Value
|Secondary air pipe pressure – Intake manifold pressure| > 7.9 kPa (59.44 mmHg, 2.3 inHg)
15WRX_STI_US_EN.book 221 ージ 20  
GD(STI)-222
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GA:DTC P2432 SECONDARY AIR INJECTION SYSTEM AIR FLOW /PRESSURE
SENSOR CIRCUIT LOW
1. OUTLINE OF DIAGNOSIS
Judge as NG if out of specification.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage < 0.573 V
15WRX_STI_US_EN.book 222 ージ 20  
GD(STI)-223
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GB:DTC P2433 SECONDARY AIR INJECTION SYSTEM AIR FLOW /PRESSURE
SENSOR CIRCUIT HIGH
1. OUTLINE OF DIAGNOSIS
Judge as NG if out of specification.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
None
Judgment Value
Malfunction Criteria Threshold Value
Output voltage > 4.916 V
15WRX_STI_US_EN.book 223 ージ 20  
GD(STI)-224
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GC:DTC P2440 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE
STUCK OPEN (BANK1)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0410. <Ref. to GD(STI)-108, DTC P0410 SECONDARY AIR IN-
JECTION SYSTEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
GD:DTC P2441 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE
STUCK CLOSED (BANK1)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0410. <Ref. to GD(STI)-108, DTC P0410 SECONDARY AIR IN-
JECTION SYSTEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
GE:DTC P2442 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE
STUCK OPEN (BANK2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0410. <Ref. to GD(STI)-108, DTC P0410 SECONDARY AIR IN-
JECTION SYSTEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
GF:DTC P2443 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE
STUCK CLOSED (BANK2)
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC P0410. <Ref. to GD(STI)-108, DTC P0410 SECONDARY AIR IN-
JECTION SYSTEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
15WRX_STI_US_EN.book 224 ージ 20  
GD(STI)-225
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GG:DTC P2444 SECONDARY AIR INJECTION SYSTEM PUMP STUCK ON
1. OUTLINE OF DIAGNOSIS
Detect the secondary air pump malfunction (always ON).
After the secondary air pump turns to OFF, judge as NG if the secondary air pipe pressure is higher than that
before the secondary air pump operation.
2. ENABLE CONDITIONS
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
4. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Time Needed for Diagnosis: 8000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 7 V
Time since secondary air control completion 3000 ms
and
8000 ms
Engine In operation
Judgment Value
Malfunction Criteria Threshold Value
Secondary air pipe pressure – Secondary air pipe pressure before operation > 6.7 kPa (50 mmHg, 2 inHg)
15WRX_STI_US_EN.book 225 ージ 20  
GD(STI)-226
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GH:DTC P2530 IGNITION SWITCH RUN POSITION CIRCUIT
1. OUTLINE OF DIAGNOSIS
Detect instantaneous open in ignition switch input circuit to ECM.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
ECM monitors the voltage of the ignition switch input circuit. Judge as ignition switch ON when the voltage
is the specified value or more.
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously after the enable conditions have been established.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established within the predetermined time.
Time Needed for Diagnosis: 5000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Engine speed 600 rpm
Judgment Value
Malfunction Criteria Threshold Value
Number of instantaneous opens in ignition switch input circuit 5 time(s)
15WRX_STI_US_EN.book 226 ージ 20  
GD(STI)-227
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GI: DTC P2610 ECM/PCM INTERNAL ENGINE OFF TIMER PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Detect malfunction of soaking timer IC by the five diagnoses below.
Monitor Number Explanation Time required for diagnosis
Monitor #1
<Timer diagnosis>
Perform diagnosis of the soaking timer IC accuracy 128 ms
Monitor #2
<Full count diagnosis>
Perform diagnosis of the soaking timer IC counter
function
128 ms
Monitor #3
<Soaking timer IC setting diagnosis>
Perform diagnosis of communication between ECM
and soaking timer IC
128 ms
Monitor #4
<Timer diagnosis (during soaking)>
Perform diagnosis of the soaking timer IC accuracy
during soaking
None
Monitor #5
<Wake-up diagnosis>
Perform diagnosis of wake-up function None
#1
0 (h)
ON
OFF
OFF
ON
5 (h)
#2 #3 #4 #3 #5
EN-10762
This is an example of ELCM monitor execution at soak time of 5 hours.
Driving time
Main relay
Wake up command for ELCM monitors
Soak time
Ignition switch
ECM counter
Soak timer IC counter
Time (h)
15WRX_STI_US_EN.book 227 ージ 20  
GD(STI)-228
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
2. COMPONENT DESCRIPTION
The soaking timer IC is built into the ECM.
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once when the ignition switch is OFF and when the ignition switch is ON after the
soaking of one hour or more.
Secondary Parameters Enable Conditions
<Timer diagnosis>
Battery voltage 10.9 V
Ignition switch OFF
Elapsed time after starting the engine > 600 s
and
< 61380 s
<Full count diagnosis>
Battery voltage 10.9 V
Ignition switch OFF
Counter in ECM 4 s
<Soaking timer IC setting diagnosis>
Battery voltage 10.9 V
Ignition switch OFF
<Timer diagnosis (during soaking)>
Battery voltage 10.9 V
Ignition switch OFF
<Wake-up diagnosis>
Ignition switch ON
Time in the soaking timer IC > 3600 s
OFF
ON
#1
0 (h)
EN-10763
OFF
ON
5 (h) 7 (h)
#2 #3 #4 #3 #3#4#3 #3#4#3 #5
9.5 (h)
This is an example of ELCM monitor execution at soak time of 9.5 hours.
Wake up command for ELCM monitors
CanceledCanceled Execute
Soak time
retryretry
Time (h)
Driving time
Main relay
Ignition switch
ECM counter
Soak timer IC counter
15WRX_STI_US_EN.book 228 ージ 20  
GD(STI)-229
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
<Timer diagnosis>
Start the count up operation of counters in ECM and in soaking timer IC when the engine is started.
Judge as timer malfunction if the difference between the counter in ECM and counter in soaking timer IC ex-
ceeds the allowable limit when the ignition switch is OFF.
Judge as NG when the following conditions are established.
Judgment Value
Malfunction Criteria Threshold Value
|osoaktimcpu – osoaktimic| / osoaktimcpu
osoaktimcpu = Counter in ECM
osoaktimic = Counter in soaking timer IC
> 0.24
OK
OFF
ON
EN-10764
OFF
ON
Main relay
Ignition switch
ECM counter
Soak timer IC counter
Detection timing
Malfunction
Malfunction
Monitor
15WRX_STI_US_EN.book 229 ージ 20  
GD(STI)-230
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
<Full count diagnosis>
Reset the counter in soaking timer IC and start the count up operation.
Judge as full count diagnosis malfunction if counter in soaking timer IC is not $3FF (1023 count) after 4 sec-
onds.
Judge as NG when the following conditions are established.
Judgment Value
Malfunction Criteria Threshold Value
osoakfcntic
osoakfcntic = Counter in soaking timer IC
$3FF (1023 count)
OK
OFF
ON
EN-10765
OFF
ON
Main relay
Ignition switch
ECM counter
Soak timer IC counter
Detection timing
1023 counts
Malfunction
Monitor
4 sec
15WRX_STI_US_EN.book 230 ージ 20  
GD(STI)-231
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
<Soaking timer IC setting diagnosis>
When setting the activation setting time to soaking timer IC, compare the writing value to soaking timer IC
with read out value. Judge as malfunction if the values do not match 3 times in a row.
Judge as NG when the following conditions are established.
Judgment Value
Malfunction Criteria Threshold Value
Writing value and read out value when setting the soaking timer Unmatch
OFF
ON
0 (h)
EN-10766
OFF
ON
5 (h) 7 (h)
#3 #3 #3#3 #3#3
9.5 (h)
Main relay
Ignition switch
ECM counter
Soak timer IC counter
Wake up command for ELCM monitors
Time (h)
Soak time
15WRX_STI_US_EN.book 231 ージ 20  
GD(STI)-232
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
<Timer diagnosis (during soaking)>
Wake-up at the predetermined interval until 5, 7 or 9.5 hours have passed after the ignition switch is OFF,
and compare the counter in soaking timer IC with the counter in ECM.
Judge as malfunction if the counter in soaking timer IC is counted up to maximum value (1023 count) when
the counter in ECM is 1636 ms, or if the counter in soaking timer IC is not counted up to maximum value
(1023 count) when the counter in ECM is 2456 ms.
0 (h) 5 (h) 7 (h)
OFF
ON
EN-10767
OFF
ON
OK
1.636 sec 2.456 sec
Main relay
Ignition switch
ECM counter
Soak timer IC counter
Wake up command for ELCM monitors
Time (h)
0 count
1023 counts
Malfunction
Malfunction
OK time
interval
Main relay
0 secECM counter
Soak timer IC counter
Wake up period (3 sec)
Enlarged
15WRX_STI_US_EN.book 232 ージ 20  
GD(STI)-233
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Judge as NG when the following conditions are established.
<Wake-up diagnosis>
Store the number of wake-up activation when the ECM wakes up by the soaking timer IC.
Next time when the ignition switch is ON, if the number of wake-up activation does not reach the predeter-
mined value even though the counter in soaking timer IC operates 1 hour or more, judge as wake-up mal-
function.
Judge as NG when the following conditions are established.
Judgment Value
Malfunction Criteria Threshold Value
When any one of the followings is established:
• All of the following conditions are established.
Counter in ECM 1636 ms
Counter in soaking timer IC = $3FF (1023 count)
• All of the following conditions are established.
Counter in ECM 2456 ms
Counter in soaking timer IC $3FF (1023 count)
Judgment Value
Malfunction Criteria Threshold Value
Number of wake-up Wake-up indication count
5 (h)
OK
OFF
ON
0 (h)
EN-10768
OFF
ON
7 (h)
Number of
actual wake-up
9.5 (h)
No wake-up
ECM counter
Soak timer IC counter
Main relay
Ignition switch
No sleep
Malfunction
Detection timing
Wake up command for ELCM monitors
Time (h)
15WRX_STI_US_EN.book 233 ージ 20  
GD(STI)-234
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Approx. 5 — 9.5 hours
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
Judgment Value
Malfunction Criteria Threshold Value
Ignition switch ON
Driving cycle Completed
When any one of the followings is established:
• Timer diagnosis NG
• Full count diagnosis NG
• Soaking timer IC setting diagnosis NG
• Timer diagnosis (during soaking) NG
• Wake-up diagnosis NG
15WRX_STI_US_EN.book 234 ージ 20  
GD(STI)-235
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GJ:DTC U0073 CAN FAILURE, BUS ‘OFF’ DETECTION
1. OUTLINE OF DIAGNOSIS
Detect malfunction of CAN communication.
Judge as NG when CAN communication failure has occurred.
2. COMPONENT DESCRIPTION
(Common Specifications)
CAN Protocol 2.0 B (Active)
Frame Format: 11 Bit ID Frame (Standard Frame)
Conforms to ISO11898
Communication Speed: 500 kbps
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after starting the engine.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 436 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
bus off flag or error warning flag set (error)
15WRX_STI_US_EN.book 235 ージ 20  
GD(STI)-236
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GK:DTC U0122 CAN (VDC) DATA NOT LOADED
1. OUTLINE OF DIAGNOSIS
Detect malfunction of CAN communication.
Judge as NG when CAN communication failure has occurred between VDC CM and body integrated unit.
2. COMPONENT DESCRIPTION
(Common Specifications)
CAN Protocol 2.0 B (Active)
Frame Format: 11 Bit ID Frame (Standard Frame)
Conforms to ISO11898
Communication Speed: 500 kbps
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after starting the engine.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
GL:DTC U0155 LOST COMMUNICATION WITH INSTRUMENT PANEL CLUSTER
(IPC) CONTROL MODULE
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC U0122. <Ref. to GD(STI)-236, DTC U0122 CAN (VDC) DATA NOT
LOADED, Diagnostic Trouble Code (DTC) Detecting Criteria.>
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
ID received from control module connected to CAN None
15WRX_STI_US_EN.book 236 ージ 20  
GD(STI)-237
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
GM:DTC U0416 CAN (VDC) DATA ABNORMAL
1. OUTLINE OF DIAGNOSIS
Detect malfunction of CAN communication.
Judge as NG when data received from VDC CM and body integrated unit is not normal.
2. COMPONENT DESCRIPTION
(Common Specifications)
CAN Protocol 2.0 B (Active)
Frame Format: 11 Bit ID Frame (Standard Frame)
Conforms to ISO11898
Communication Speed: 500 kbps
3. ENABLE CONDITIONS
4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after starting the engine.
5. DIAGNOSTIC METHOD
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: 2 seconds
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
GN:DTC U0423 INVALID DATA RECEIVED FROM INSTRUMENT PANEL CLUS-
TER CONTROL MODULE
1. OUTLINE OF DIAGNOSIS
NOTE:
For the detection standard, refer to DTC U0416. <Ref. to GD(STI)-237, DTC U0416 CAN (VDC) DATA AB-
NORMAL, Diagnostic Trouble Code (DTC) Detecting Criteria.>
Secondary Parameters Enable Conditions
Battery voltage 10.9 V
Judgment Value
Malfunction Criteria Threshold Value
Data updated from control module connected to CAN None
15WRX_STI_US_EN.book 237 ージ 20  
GD(STI)-238
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
15WRX_STI_US_EN.book 238 ージ 20  
2015 WRX / WRX STI SERVICE MANUAL QUICK REFERENCE INDEX
FUJI HEAVY INDUSTRIES LTD. G1190BE3
ENGINE 2 SECTION
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.
FUEL INJECTION (FUEL SYSTEMS) FU(w/o STI)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICES)
EC(w/o STI)
INTAKE (INDUCTION) IN(w/o STI)
MECHANICAL ME(w/o STI)
EXHAUST EX(w/o STI)
COOLING CO(w/o STI)
LUBRICATION LU(w/o STI)
SPEED CONTROL SYSTEMS SP(w/o STI)
IGNITION IG(w/o STI)
STARTING/CHARGING SYSTEMS SC(w/o STI)
ENGINE (DIAGNOSTICS)
EN(w/o STI)
(diag)
GENERAL DESCRIPTION GD(w/o STI)
15WRX_STI_US_EN.book 1 ペー 01  
15WRX_STI_US_EN.book 2 ペー 01  
FUEL INJECTION (FUEL SYSTEMS)
FU(w/o STI)
Page
1. General Description ...................................................................................2
2. Throttle Body ............................................................................................15
3. Intake Manifold .........................................................................................18
4. Tumble Generator Valve Assembly .........................................................43
5. Tumble Generator Valve Actuator ............................................................45
6. Fuel Insulator ...........................................................................................46
7. Fuel Injector .............................................................................................51
8. Fuel Pressure Sensor ..............................................................................71
9. High Pressure Fuel Pump ........................................................................74
10. Engine Wiring Harness ............................................................................85
11. Engine Coolant Temperature Sensor .......................................................93
12. Engine Oil Temperature Sensor ...............................................................96
13. Crankshaft Position Sensor ......................................................................98
14. Crankshaft Position Sensor Plate ..........................................................102
15. Camshaft Position Sensor ......................................................................103
16. Oil Control Solenoid ...............................................................................108
17. Knock Sensor .........................................................................................111
18. Throttle Position Sensor .........................................................................117
19. Mass Air Flow and Intake Air Temperature Sensor ...............................118
20. Manifold Absolute Pressure and Intake Air Temperature Sensor ..........120
21. Wastegate Control Solenoid Valve ........................................................123
22. Front Oxygen (A/F) Sensor ....................................................................126
23. Rear Oxygen Sensor ..............................................................................128
24. SI-DRIVE (SUBARU Intelligent Drive) Selector .....................................131
25. Engine Control Module (ECM) ...............................................................132
26. Main Relay .............................................................................................135
27. Oxygen Sensor Relay ............................................................................137
28. Electronic Throttle Control Relay ...........................................................139
29. Fuel Pump Relay ....................................................................................141
30. Fuel Injector Relay .................................................................................143
31. Fuel Pump Control Unit ..........................................................................145
32. Fuel ........................................................................................................146
33. Fuel Tank Protector ................................................................................151
34. Fuel Tank ...............................................................................................152
35. Fuel Filler Pipe .......................................................................................163
36. Fuel Pump ..............................................................................................168
37. Fuel Level Sensor ..................................................................................173
38. Fuel Sub Level Sensor ...........................................................................176
39. Fuel Filter ...............................................................................................183
40. Fuel Delivery and Evaporation Lines .....................................................194
41. Fuel System Trouble in General ............................................................202
15WRX_STI_US_EN.book 1 ペー 01